She disabused me of the notion that stir-frying in a wok and a frying pan yield the same results: the former heats up quickly and is designed for a quick, light cooking, to achieve what the Cantonese call 'wok-fresh' food. The latter heats up more slowly and consequently cools more slowly, making the quick, light cooking difficult.
Stir-frying itself is straightforward. The wok should be heated to smoking point before oil is added. Heat should be immediately reduced once cooking begins. Chinese and Far Easterners will deliberately brown their chopped garlic and ginger, where Western cooks do not. It lends that singular toasty flavour.
Once the cooking begins, logic rules: cook the toughest, or densest ingredients first. This technique is set out below. For dishes with lots of ingredients it often pays to give the wok a quick clean between cooking stages.
This is less bother than it sounds. Once the first ingredient - tough vegetable or meat - has been cooked and put aside, the wok will need intense reheating. If it is still lined with the oil and particles of the last cooking, this can burn and taste objectionable. It also allows flavours to remain separate and distinct.
There are endless varieties of soy sauce. I have found the Chinese varieties tend to be thin and salty, Indonesian ones thick and sweet. Each has its uses. In moderation, fermented fish sauce will give depth to many stir-fries, and a quick squeeze of lemon or lime juice will pick it up. Rice wine vinegars are excellent to finish sauces or for deglazing.
A set number of condiments is useful. One Chinese friend always makes a scorching hot chilli paste to which she adds oil. A small dab on the end of chopsticks stirred well into a portion is sufficient.
And so to baak-choi. This king of oriental cabbages is more robust than spinach, more refreshing than our Western cabbage varieties. Tougher mature heads will almost always be in Chinese shops, and tender little baby varieties even have started appearing in leading supermarkets.
This can be extended for a dinner with slivered chicken, beef or pork, in which case the meat should be cooked after the baak- choi stalks. But I prefer baak- choi as a vegetable side dish, and have never enjoyed it more than when served to an amused Chinese friend during an impromptu Sunday brunch with spicy Bloody Marys, cheese omelettes, grilled smoked bacon and oven-fresh Irish soda bread.
Serves 4 as a side dish
1lb/450g baby baak-choi
2 cloves garlic, minced
same amount of ginger, minced
1/2 red chilli, de-seeded and minced
1tbs vegetable oil
1tsp sesame oil
2tsp Chinese soy sauce, less if thick and sweet
juice of 1/2 small lemon
freshly ground black pepper
Preparation: Wash and dry baak-choi. Chop off white stalks. Heat wok to smoking point on a hot stove-top. Add the vegetable oil and the sesame oil, swirl around hot wok and immediately reduce heat. Add garlic, ginger and chilli. Brown. Quickly add white baak-choi stalks. Toss with tongs until slightly wilted. Add soy sauce and greens. As they are wilting, toss together over light heat. Season and finish with fresh lemon juice just before serving.
Next week, more stir-fries. Those whose recipes we print will receive Yan-kit So's Classic Food of China (Macmillan, pounds 25). Send entries, stating the source, to Emily Green, Recipe, Weekend Features, the Independent, 40 City Road, London EC1Y 2DB.
New entries are also sought for our next category: imaginative ways to use up the Christmas leftovers. The prize will be Anne Willan's Complete Guide to Cookery (Dorling & Kindersley, pounds 19.95).