Water chestnuts-edible tubers that grow underwater-add mild crunch to cold salads and hot entrees. They're available canned, either whole or silced. Fresh water chestnuts, available in Chinese markets, are another thing all together, endowed with a much crisper texture and an incredible natural sweetness. Peel them before using.
When cooking in a wok, add the ingredients a small amount at a time in the center of the wok. As they begin to cook, move them up the sides of the wok and stir the next batch of ingredients into the middle.