The most commonand possibly most popularfood in Beijing during Chinese New Year are these dumplings. Since the New Year falls in winter, only bok choy is in season, so local cooks mix it with dry mushrooms and bamboo shoots, and serve the dumplings with black vinegar and fresh garlic. Traditionally, the cook will slip a bright, new coin into the center of a selected dumpling so the lucky eater will find some good fortune. The correct way to eat these dumplings is to poke a small hole in their centers with chopsticks so that the dipping sauce can seep inside. Look for preserved cabbage and squares of fried tofu at your local Asian market.
Soak dried mushrooms in water for about 30 minutes, or until they soften. Squeeze out water, and dice.
Cut all vegetables into small dice, and press under weights for several hours to squeeze out all liquid. Mix dry vegetables with tofu, salt, pepper, sugar and oils.
To make dumplings, place each wrapper on flat surface, spoon about 1 teaspoon filling into center and fold dough over in half. Moisten edges of each wrapper with beaten egg, and pinch shut to seal in filling. Repeat with remaining wrappers and filling until used up.
Steam dumplings over boiling water for about 5 minutes. Remove from heat, and set aside.
To serve, arrange dumplings in serving dish. To make dipping sauce, combine garlic and black vinegar, and pass with dumplings, making more sauce as needed.