BEFORE Martha Dahlen, author of A Cook's Guide to Vegetables, came to Hongkong, one week in Rome was her only experience of foreign travel - and food. What made an insulated expatriate venture into Hongkong's markets was not so much a love of cooking as a combination of professional interest and personal curiosity. Born and raised in Virginia, Dahlen trained as a horticulturalist and practised botany. ''I have always been interested in how people used plants, eating them is the single biggest use,'' she said. ''When I arrived here, I was fascinated by the vegetables in the markets and decided to find out as much as I could.'' As an American, Dahlen believes she has inherited an adolescent culture. ''We have an enthusiasm and innate curiosity which is perhaps not shared by Europeans who grow up exposed to different cultures,'' she said. ''Where Westerners have a more cosmetic approach to cooking - what a dish looks like, how quick it is to prepare - the Chinese are more interested in how food affects the body,'' she said. Judgements are not Dahlen's business. ''As a scientist, I keep an open mind,'' she said. ''I try things and if I find they taste good and make me feel good, I stay with them.'' The diet which she ''stays with'' is simple and nutritious. It is based on fresh fruit for breakfast, whatever the cafe near her workplace is offering - baked potato with vegetables and noodles - for lunch, and a wholegrain, green vegetable and protein dish for dinner. ''I like home-style food not sumptuous feasts,'' said Dahlen. ''I rarely eat meat and prefer fresh fruit and vegetables whenever possible. The most important aspect of any meal is to get a balance of colour, flavour and texture.'' Because of her knowledge of market fare, Dahlen sticks to seasonal foods when planning a meal. With Chinese New Year approaching, she would serve a typical - but simple - lunch. The meal would consist of as many dishes as there are guests. A traditional winter soup made from either radish, carrots and pork or green papaya; steamed dau miu (green pea shoots); steamed fish; rice; chicken braised with chestnuts; and either a ''New Year's prosperity dish'' made of stir-fried celery, seaweed, gluten puffs or lo hon jai casserole. LO HON JAI CASSEROLE Note: Quantities are according to taste; the dried ingredients can be bought pre-packaged during Chinese New Year. Dried ingredients Gingko nuts (baak gwoh) Dried oysters (ho see) Seahair (faat choi) Red dates (hoeng jo) Bean sticks (jee jook) Lily buds or golden needles (gum jum choy) Black mushrooms (doeng gwu) Wood ear mushrooms (wan yee) Mungbean vermicelli (fuun see) Fresh ingredients Soyabean sprouts (dai dau nga choi) Peking cabbage (wong nga baak) Peapods (dau miu) Seasoning Oyster sauce Soy sauce Red beancurd cheese (namm yu) Half teaspoon of sugar Crack the gingko nuts, remove the nutmeat and peel off the thin skin. Soak the dried ingredients. Trim the soyabean sprouts and peapods, and chop the cabbage. In a dry wok over a high heat, parch the sprouts until wilted and remove. Add a generous amount of oil to the wok and saute the oysters and black mushrooms until fragrant. Add the sprouts and the dried drained ingredients except the vermicelli. Use one square of red beancurd cheese per 500 grams of vegetables: mash it into a smooth paste and add to the wok with the other seasonings. Cover and braise for 15-20 minutes. Add the vermicelli and continue braising for another 15-20 minutes. Stir-fry the peapods and cabbage separately. Add the cabbage and when it has softened, add the peapods. Toss, adjust seasoning, and serve. - RACHEL WELLER
