40 dried lily buds (about 1/2 ounce)*
1 tablespoon dried wood ear mushrooms
1/3 cup dried shiitake mushrooms
5 cups chicken stock, low-sodium (do not substitute vegetable or mushroom broth)
1/2 cup drained canned bamboo shoots, rinsed and julienned
2 teaspoons minced fresh ginger
2 cups Napa cabbage, chopped
3 tablespoons cornstarch
3 tablespoons cold water
1 large egg, beaten
2 teaspoons toasted sesame oil
4 ounces firm tofu, drained and cut into 1/3-inch cubes
1-1/2 tablespoons soy sauce
2 tablespoons Chinkiang vinegar*
1 teaspoon white pepper powder
*Note: these items are very hard to find. Do not use substitutes. Best to order ahead of time online.
Place lily buds and mushrooms in a small bowl, and add very hot water to cover by 1 inch. Let soak until softened, about 30 minutes. Drain and rinse thoroughly. Trim and discard tough ends from buds, and cut in half crosswise. Thinly slice mushrooms.
Stir together lily buds, mushrooms, chicken stock, bamboo shoots, and ginger in a large saucepan over high. When the soup starts to simmer, add Napa cabbage and turn to medium-low heat. Cook until the Napa cabbage turns tender, 5 to 8 minutes.
Whisk together cornstarch and 3 tablespoons water in a small bowl. Whisk cornstarch mixture into chicken stock mixture in a slow, steady stream; cook 1 minute. Pour beaten egg into chicken stock mixture in a slow, steady stream, stirring gently.
Stir in tofu, soy sauce, and sesame oil, and cook another 2 minutes.
In small bowl, add the vinegar and pepper. Whisk to blend thoroughly. Stir into soup mixture and serve immediately.