Sichuan Preserved Vegetable: Cured in ground chile pepper and salt, this member of the cabbage family, called swollen stem mustard and native to Sichuan, is, like the olive, grown only to be cured. Chopped, the vegetable is used in dumpling stuffings and dipping sauces; julienned, it’s stir-fried with pork; simply sliced and cooked in plain water, it makes a rich vegetarian stock. Available in cans and in bulk in Asian markets, preserved vegetable should be sliced, rinsed in cold water (it’s fairly salty), and dried before using.
Dried Lily Buds, a.k.a. Golden Needles: Often used with tree ear mushrooms,jin zhen, as they are called in Chinese, are thought to keep the arteries clear. They are slightly sour, with a mushroom flavor and a vinegar-like scent, and are a staple of hot-and-sour soup and mu shu pork. Mistakenly called tiger lily buds, golden needles are actually a kind of daylily, plucked and dried unopened. Available in eight-ounce packages, they should be light golden and pliable, not brown and brittle. To use, soak in warm water to cover for 20 minutes or so, then cut off the tough tips and discard, and, to release their fragrance, pull each bud into two or three shreds lengthwise.
Gan-cai-sun (dried, fermented vegetables): The simple combination of bamboo shoots and mustard greens is transformed by a method of salting and curing that has been practiced in China for some 2,000 years. Gan-cai-sun looks and smells like a black tea and adds an intensely earthy flavor to steamed meats and broths. To use, rinse the vegetables of their saltiness. Look for them in stores specializing in foods from Shanghai or Hangzhou.
Bird’s Nest: One of the world’s culinary curiosities and one of the most expensive items you can legally buy for consumption, bird’s nest is the regurgitated spittle of a cave-dwelling swift, which uses this substance, secreted by special glands, in nest building. Harvested in limestone caverns along the tropical Asian coast, the finest can sell for more than $200 an ounce. Traditionally, bird’s nest is enjoyed in a banquet-style soup in either a clear, rich stock with a fancy garnish such as steamed pigeon eggs and ham or a “chicken velvet”-style dish with egg white and wine. It’s also eaten cold in a light syrup.