If you've eaten Chinese vegetarian food, you've probably tasted wheat gluten, which is often cooked, flavoured and shaped so it (slightly) resembles meat.
What is it? Gluten is the protein in wheat flour that gives it its elasticity, trapping the air bubbles (from the yeast or other leavening) that make the bread light.
In Chinese and Japanese vegetarian cuisine, gluten is traditionally extracted from wheat flour by making a firm dough of flour and water, kneading it to develop the protein then washing the dough in frequent changes of water until the water remains clear. This pure gluten can be fried, which turns it into light, hollow puffs; layered, pressed and simmered in a rich sauce; or shaped into blocks (similar to beancurd) and steamed or simmered.
What to look for? Smell and taste. If you buy plain gluten - whether puffs or blocks - you want a clean flavour and smell that you can season as desired. Fried gluten puffs should smell of clean oil.
What else? The wheat-intolerant aside, gluten can make a good, healthy alternative to meat. How to use? The 'mock meats' served at Buddhist vegetarian restaurants are best left to the professionals because they require skill to make. Although they can be delicious, if you expect them to taste like meat, you'll probably be disappointed.
Gluten is also used in western mock-meat dishes, such as fake hamburgers, turkey, bacon, ham and sausages. As with the Buddhist varieties, these bear little resemblance to the real thing. Wheat gluten is almost tasteless on its own but it's good at soaking up flavours. Seasonings should be strong to compensate for its blandness. For a simple dish, simmer gluten puffs in well-flavoured broth (the puffs will deflate); they are especially delicious in the broth used to cook hotpot, after all the meats, seafood and vegetables have been cooked. Wheat gluten - the pressed type (cut into cubes) or puffs - can be simmered in a dark, rich sauce made with soy sauce, oyster (or mushroom, if you're vegetarian) sauce, shiitake mushrooms, star anise, cinnamon and fresh bamboo shoots. Serve this dish just slightly warm, or at room temperature. Turn pressed gluten into a refreshing cold dish by slicing it thinly and tossing with julienned carrots, Chinese white radish, celery, soy sauce and lots of sesame oil.