This is the fifth and final installment of my monthly column in Chengdoo Citylife Magazine, 'Your Chuancai Cupboard'. This month: Vinegar.

Vinegar, 醋， is among the most important condiments in Chinese cooking. One of the so-called ‘Seven Essentials’ of the traditional Chinese kitchen (along with firewood, rice, oil, salt, soy sauce and tea), vinegar’s importance in Chinese culture even extends to the language – in Mandarin, ‘to eat vinegar’， 吃醋， means to be jealous of somebody or something.

Vinegar is said to have been invented in China during the Xia Dynasty in around 2000 BC, and has been commercially produced from as early as the 1st century AD. It is particularly prized for its sourness (one of the four essential tastes, along with salty, sweet and bitter), and it is also widely used in Traditional Chinese Medicine for the treatment of all manner of ailments, from high blood pressure to athlete’s foot; TCM practitioners use vinegar to promote warm (yang) energy, and it is said to be particularly effectively when eaten in autumn.

Though commonly referred to as rice vinegar, Chinese vinegars are in fact usually made from a combination of ingredients that often includes rice (both white and black), but may also utilize wheat, millet, and sorghum. The color of Chinese vinegars ranges widely, from clear to inky black, and so too does the taste, from strongly acidic to smoky and mild.

Sichuan is one of China’s four most famous producers of vinegar; the other three are Zhejiang, Shanxi, and Fujian. Sichuan’s capital of vinegar production is Langzhong, in the northeast of the province, where, unique among Chinese vinegars, bran is the primary ingredient.

Baoning vinegar is the most famous and widely used brand made in Langzhong, but others do exist – I particularly like that made by the Langzhou 朗州 company, which is sweeter than the Baoning variety. At the Langzhou Vinegar Company, the traditional method of production is still in use, and goes as follows.

First, rice and dried corn kernels are steamed, and then are added to a mixture of bran and over 60 traditional Chinese medicines and herbs. This mixture is then left to ferment in sealed containers for up to 60 days, then is mixed with spring water and seeped for 2 to 3 days. Finally, the liquid is strained, boiled, bottled and is thus ready for use.

Though not as commonly used in Sichuan’s cuisine as in other parts of China, vinegar is nonetheless an indispensable part of the Sichuanese kitchen. Black vinegar is more commonly used than white vinegar, but the latter does feature particularly in cold dishes. Black vinegar can be bought at dried good stalls at markets, while supermarkets usually stock a wide variety of many different types. Outside of China, Chinkiang vinegar, widely available in Oriental supermarkets, is an acceptable substitute.

Perhaps the most famous Sichuanese dish that uses vinegar is the ridiculously easy Tiger-Skin Peppers， 虎皮请教， pictured above. Below is a recipe I’ve adapted from Fuchsia Dunlop’s Sichuan Cookery; the size of green pepper you use for this dish can vary – if you like it spicy, go for the long, thin ones; if not, go for a larger variety.

Tiger-Skin Peppers 虎皮请教

4 green peppers (capsicum)
Cooking oil
1-2 tablespoons black vinegar
1/2 teaspoon sugar
Salt to taste

1. If using large green peppers, quarter and discard the seeds and stems. If using the small kind, just squash slightly with the side of your cleaver. Mix the sugar and salt into the vinegar until they are completely dissolved.
2. Heat about 2 tablespoons of oil in a wok until smoking, and then add the peppers. Stir-fry over a medium heat for 5-6 minutes, or until the peppers are tender and their skins blistered and streaky.
3. Finally, remove the peppers to a serving dish, drizzle with the vinegar mixture and serve.

Here is the fourth installment of my monthly column in Chengdoo Citylife Magazine, 'Your Chuancai Cupboard'. This month: Ya Cai.

Ya cai, is one of Sichuan’s most famous and distinctive food products. Made from the stems of a variety of mustard green, it’s fragrant and distinctive flavor is found in many of the regions dishes. Said to have been invented in the early 19th century, ya cai is just one of the myriad different preserved vegetables used in Sichuan’s cuisine, including zha cai, da tou cai ('big head vegetable')and many other regional varieties.

Ya cai’s primary ingredient is jie mo cai, a type of mustard green native to Southeast Sichuan. Around 4-5 months after being planted, the mustard green plants are harvested in the 9th lunar month. The leaves are then discarded, the stems sliced into even strips, and the strips hung out on poles to dry.

The making of ya cai is unusual among Sichuanese ingredients, in that while doubanjiang (chilli bean paste) and dou chi (fermented black beans) only require one fermentation stage, ya cai demands two. Once sufficiently dry, the mustard green stems are mixed with salt and left to ferment in sealed containers for 3 to 6 months – small ceramic pots called tu tan are traditionally used. This is the first of the two fermentation stages.

Once the first stage is complete, the mustard green stems are boiled with brown sugar for 8 to 9 hours, and are hung up to dry out once more. Now, star anise, Sichuan pepper, and other spices are added, and again, the mustard green stems are left to ferment in sealed containers for another 3 to 6 months.

In Chengdu’s markets you can sometimes find un-cut ya cai – long, straggly strips of green-brown vegetable, bought by weight – but mostly ya cai is bought already chopped up in small, sealed packages. When buying ya cai make sure to buy a brand based in Yibin, the city about 250km southeast of Chengdu which is the most celebrated producer of this ingredient. Once opened, you should store ya cai in a sealed container in a cool, dry place.

Though a few different brands exist, by far the most common is Yibin’s Sui Mi Ya Cai Company, who apparently started the practice of chopping up ya cai, hence the name – sui mi means crushed rice, referring to the appearance of the company’s bitty, pre-cut ya cai.

Ya cai is often mixed with pork for the stuffing of baozi, and is also a vital ingredient in Yibin’s signature dish, ran mian (‘burning noodles’). But it is perhaps most famously used in one of Sichuan’s most popular vegetable dishes, Dry-Fried Green beans. I’ve eaten countless different versions of this dish, but this one is my favorite.

Dry-fried Green Beans

250g green beans
2 tablespoons ya cai
1 tablespoon fermented black beans (dou chi), rinsed and drained
5 dried chillies, halved and seeds discarded
1 teaspoon Sichuan pepper (huajiao)
3 cloves of garlic, thinly sliced, and the same amount of ginger, thinly sliced
3 spring onions, cut into 3cm lengths
50g minced pork (optional)
Cooking oil
Salt to taste

1. Top and tail the green beans, and cut into 5cm lengths.
2. Heat your wok, and add about a tablespoon of cooking oil. Once hot, add the pork and stir-fry for a few minutes until cooked through, and then set aside.
3. Add a tablespoon of oil to the wok, and once hot add the beans, stir-fry for a couple of minutes, and then add another 1-2 tablespoons of oil. Stir-fry for another 3-5 minutes, or until the beans are tender. Remove from the wok and set aside.
4. Add another tablespoon of oil to the wok, and once hot add the garlic and ginger slices. Stir-fry on a moderate heat for about 30 seconds, and then add the chilies and Sichuan pepper. Stir-fry for another 30 seconds, taking care not to burn the spices, and now add the ya cai and dou chi and stir-fry for another 30 seconds.
5. Finally, add the spring onions (and the pork, if using), and return the beans to the wok. Stir-fry for another minute or so, add salt to taste, remove to a serving dish and serve.

Here is the third installment of my monthly column in Chengdoo Citylife Magazine, 'Your Chuancai Cupboard'. This month: Dou Chi.

Dou chi 豆豉, or fermented black beans in English, may not be Sichuan’s most famous product, but these intensely flavored little nuggets nonetheless make an appearance in many of the region’s most famous dishes. As well as playing an important role in Sichuan’s cuisine, dou chi are also widely used across China (particularly in the Cantonese tradition), and the ubiquitous Chinese restaurant staple ‘black bean sauce’ is eaten in Chinatowns from Los Angeles to Lagos.

The English name ‘fermented black beans’ is, however, a misnomer. The bean used to make dou chi is not the black turtle bean (commonly used in the cuisine of the Americas and the Carribean), but the soybean, which is soaked, steamed, and then fermented to produce a salty, pungent flavoring.

Variations of dou chi abound across Asia, the most famous examples being Japanese Natto, Korean Cheonggukjang, and Himalayan Kinema. But while these versions rely on added bacteria to speed up the fermentation process, Chinese dou chi usually only have salt added, making their fermenting time much longer, and their taste less overwhelming than their Japanese and Korean counterparts.

As well as being one of the most widely used of Chinese cooking ingredients, dou chi is also one of the oldest. Scholars believe them to have been used in cooking as far back as the Han Dynasty (206 BC – 220 AD), making them one of the earliest known soy products in history. And not only are they tasty, but dou chi are also said to be good for your health, used by Traditional Chinese Medicine practitioners to relieve irritability, restlessness, and insomnia.

Sichuan’s most famous dou chi is made in eastern Yongchuan County, but although modern technology is often used to speed up the lengthy traditional method, a few other small producers still dot the Sichuan countryside. One of these is the Southwest Flavorings Company, who make dou chi, fermented tofu and many other traditional Chinese cooking ingredients at their factory in Longquan, an hour from Chengdu. Here, the process from dried soy bean to finished product takes a whole year.

First, the dried soybeans are soaked in water, and then steamed till soft. Next, any remaining liquid is squeezed out of them, salt added, and then the beans are packed into sealed containers and left to ferment for many months. At the Southwest Flavorings Company, the dou chi is available in ‘original flavor’, or with other ingredients are added, such as chilli or sesame seeds.

In China, dou chi can be bought loose in markets, and is also available in small sealed packages from both markets and supermarkets. Outside of China, packets of 'Fermented Black Beans' can be bought at most Chinese or Asian stores. When buying dou chi, try to look for beans that are oily, plump and shiny, and remember to rinse them before use to remove any grit.

I like to add dou chi in small quantities to liven-up simple stir-fries, and it’s particularly good paired with fish. But it is perhaps most famously used in the much-loved Sichuan staple, Twice-cooked Pork, a recipe for which I’ve adapted from Fuchsia Dunlop’s Sichuan Cookery and provided on the right.

Twice-cooked Pork 回锅肉

300-400g half fat, half lean pork, in one piece
1 small piece of fresh ginger, sliced
8 suan miao, ‘green garlics’ (spring onions are also fine)
1 tablespoon chilli bean paste (doubanjiang)
1 teaspoon sweet wheat paste (tianmianjiang)
1 tablespoon dou chi
1 teaspoon dark soy sauce
1 teaspoon sugar
Salt

1. Bring a large pan of water to the boil. Add the ginger and the pork piece. Return to the boil, and then simmer at a low heat for about 20-30 minutes, until the pork is just cooked. Remove the pork, allow to cool, then place in a bowl with a little of the cooking liquid and refrigerate for a couple of hours (or overnight).
2. When the meat has cooled, slice it as thinly as possible, with each slice half fat and half lean.
3. Wash, top and tail the green garlics, and slice into 3cm-long chunks.
4. Heat the wok, and add about 2 tablespoon of cooking oil. Once hot, add the pork slices and stir-fry until they are slightly brown.
5. Now, push the pork to the side of the wok, and add the chilli bean paste to the space you made. Stir-fry for about 30 seconds, until the oil has turned red, then add the sweet wheat paste and dou chi and stir-fry for another few seconds. Now mix everything in the wok together, and add the soy sauce, sugar and salt to taste. You can add a little of the pork cooking liquid if it get too dry.
6. Finally, add the green garlics, mix and stir-fry until they are just cooked. Remove the finished dish to a serving plate, and eat with steamed rice.

While I was in France this summer, helping out on the singing course that my mum organises, I was entreated many times to cook a Chinese dish. Though at first I was enthusiastic about this idea, I began to get cold feet when I realized that, being in deepest rural France, I could get very few of the necessary ingredients. I worried that anything I produced would be inauthentic, and thus no good.

After much cajoling, however, I gave in, and decided to cook a cold aubergine dish. This was a dish I’d made many times in China, but it needed some serious adaptation for cooking in France. I did have with me some of the authentic Chinese ingredients, such as ground chilies and fermented black beans, but everything else was just whatever I had to hand.

The result was a somewhat odd, Asian-European fusion dish, which surprisingly, actually ended up being quite good. Given the improvisational nature of its creation, writing a recipe for this dish is, I know, a bit contradictory in spirit. Nonetheless, I thought I’d write it up for those occasions when one wants Asian flavour, but may lack a few of the ingredients.

Sichuan-en-France Cold Aubergine

1 aubergine
Cooking oil
1 tablespoon of any Asian soy sauce (Tamari and Shoyu are both fine)
1 tablespoon cider, wine or fruit vinegar
1 tablespoon chili oil (see below)
1 tablespoon sugar
1 tablespoon fermented black beans (dou chi), rinsed and drained
Salt to taste
Fresh mint leaves, roughly chopped

1. First, make the chili oil by heating a jarful of cooking oil in a frying pan or wok, and once smoking hot, adding it to a bowl containing 2-3 tablespoons of ground chilies. Mix well, and allow to cool before using.
2. Chop the aubergine into finger-length chunks, toss in some cooking oil, and then roast in a hot oven until thoroughly cooked.
3. Make the sauce by combining the soy sauce and vinegar with the sugar in a small bowl. Mix well so as to dissolve the sugar in the liquid, and then add the chili oil, fermented black beans and salt.
4. Once the cooked aubergines have cooled to room temperature, place on a serving plate. Drizzle with the sauce, garnish with the mint leaves, and serve.

Here is the second installment of my monthly column in Chengdoo Citylife Magazine, 'Your Chuancai Cupboard'. This month: Sichuan Pepper.

Sichuan pepper, or huājiāo （花椒） in Chinese, is one of the most loved, and simultaneously, one of the most hated of Chinese spices. Some people abhor its ‘soapy’ aroma, and pick out the peppercorns from a dish with distaste; others positively seek them out to enjoy their characteristic numbing flavour to the fullest.

Sichuan pepper appears in many of the most famous Sichuanese dishes, and its flavour is perhaps the most characteristic aspect of the region’s cooking – others, such as Hunan and Guizhou, use just as much chilli, but none use huajiao with such a liberal hand as the Sichuanese. It is also worth noting that huajiao’s appearance in Sichuan cuisine far predates that of chillies.

Today, Sichuan pepper is most frequently fried with dried chillies, a method that brings out its smoky tones (for example in Kung Pao Chicken), but it is also dry-fried and ground to a powder (as in Mapo Tofu), and even occasionally used raw (as in Jiao Ma Ji Pian – chicken slices in a Sichuan pepper sauce). Sichuan pepper is also one of the ingredients in the famous (and highly variable) Chinese ‘five-spice’ mixture, and is also used in various other Asian cuisines, including Japanese, Korean and Indonesian.

In spite of its name, Sichuan pepper is in fact related neither to black pepper nor chilli, but is the outer husk of the fruit of the prickly ash tree, Zanthoxylum. This somewhat stunted tree (thorny branches bare in the winter, covered by dark green, pale-edged leaves in the summer), produces its harvest in August: slightly knobbly, dusky pink balls, gathered in busy clusters – a stunning contrast to their surrounding dark leaves.

Qingxi village in Hanyuan County (about 300km south-west of Chengdu) is where the most prized and famous Sichuan pepper is grown. Its history here is long and illustrious; it is mentioned in the foundational Book of Songs, thought to be compiled by Confucius himself, and Qingxi’s Sichuan pepper was for many centuries sent in tribute to the imperial court of China’s emperors.

When I visited Qingxi, only a few weeks before the harvest, the trees were positively dripping with the peppercorns, and their lemony aroma reached me before I was even close enough to touch them. I learnt from villagers that once picked, some of the peppercorns would be used fresh to make huajiao-flavoured oil; the rest would be left to dry in the sun, laid out in bamboo baskets, until the skin has cracked to reveal the shiny black seeds within.

The seeds would then be shaken from the husks and discarded, and the leftover husks are thus ready for use in cooking.

You too can make the arduous journey to buy Sichuan pepper from the very village where it is produced, but for those not quite as huajiao-obsessed as me, just try to buy a brand from Hanyuan County. I also recommend buying Sichuan pepper in pre-sealed packets, not loose, as its flavour diminishes rapidly if not kept in a sealed container. For those not in China, Sichuan pepper can be bought online from specialist suppliers (such as the Cool Chile Company), and for British readers, is available in most supermarkets in the Bart’s spices range.

As mentioned earlier, Sichuan pepper is delicious fried with dried chillies; this method, called qiang in Chinese, can be used in combination with all manner of fresh vegetables – I like it particularly with slithers of round courgette (zucchini). But perhaps the most famous of Sichuanese dishes that uses Sichuan pepper is Mapo Tofu, a recipe for which I’ve adapted from Fuchsia Dunlop’s Sichuan Cookery and which you can find below.

Mapo Tofu 麻婆豆腐

1 block of tofu
3-4 spring onions (scallions)
Vegetable or peanut oil
150g minced beef (optional)
2 tablespoons chilli-bean paste (doubanjiang)
1 tablespoon fermented soy beans (dou chi), rinsed and drained
200ml water
1 teaspoon sugar
2 teaspoons light soy sauce
1 teaspoon of cornstarch mixed with 1 tablespoon of water
1 teaspoon Sichuan pepper

1. Cut the tofu into 2cm cubes and leave to steep in very hot, salted water. Slice the spring onions into 3cm-long chunks. Dry-fry the Sichuan pepper in a hot wok until smoking, tip out into a pestle-and-mortar and then grind to a fine powder (you can use pre-ground Sichuan pepper, but it won’t taste as good).
2. If using the beef, pour about 2 tablespoons of oil into a wok and heat. Once smoking, add the minced beef and fry until a little brown and set aside.
3. Add another tablespoon or so of oil, heat and add the chilli-bean paste. Fry for about 30 seconds, taking care not to let it burn, and then add the fermented soy beans and cook for another 30 seconds.
4. Pour in the water, add the sugar, soy sauce and salt to taste and now add the drained tofu cubes. Simmer for about 5 minutes, to allow the tofu to absorb the flavours.
5. Add the spring onions (scallions) and gently stir in. Once they are just cooked, add the starch-and-water mixture to thicken the sauce. Finally, pour everything into a serving dish, scatter with the cooked minced beef and the ground Sichuan pepper and serve.