Soak Dried Shiitake Mushroom (3) and Wood Ear Mushrooms (1 ounce) in hot water until they have reconstituted, about 20-30 minutes.
Squeeze out any excess water from the mushrooms, then cut into thin slices.
Mix Corn Starch (3 tablespoon) with Water (1/2 cup). Stir well, then set aside.
Bring Chicken Stock (6 cup) to a boil in a large pot over medium-high heat.
In a small bowl, combine Apple Cider Vinegar (1/2 cup), Soy Sauce (2 tablespoon), Brown Sugar (1 tablespoon), Sesame Oil (3 teaspoon), and Dark Soy Sauce (1 teaspoon). Pour this sauce mixture into the pot of chicken stock.
Add the sliced mushrooms to the soup, followed by the Bamboo Shoots (3/4 cup).
Give the cornstarch mixture a good stir, then pour it into the soup. Stir the soup immediately to allow the cornstarch to thicken the soup evenly.
Add Chili Oil (2 teaspoon).
Pour the Egg (2) into the soup in a slow, steady stream. While pouring the eggs into the soup, use a pair of chopsticks to swirl the soup. Swirl quickly to get a thin, silky egg consistency, or swirl slowly to get a chunkier texture.
Add the Tofu (1/2 cup) and the Ground White Pepper (3 dash). Stir to combine all ingredients.
Transfer soup to serving bowls and top with Scallion (2 stalk). Serve and enjoy!