Put the wood ears in a small bowl and cover with boiling water. Let stand for 30 minutes to reconstitute. Drain and rinse the wood ears; discard any hard clusters in the centers.
Heat the oil in a wok or large pot over medium-high flame. Add the ginger, chili paste, wood ears, bamboo shoots, and pork; cook and stir for 1 minute to infuse the flavor. Combine the soy sauce, vinegar, salt, pepper, and sugar in a small bowl, pour it into the wok and toss everything together - it should smell really fragrant. Pour in the Chinese Chicken Stock, bring the soup to a boil, and simmer for 10 minutes. Add the tofu and cook for 3 minutes.
Dissolve the cornstarch in the water and stir until smooth. Mix the slurry into the soup and continue to simmer until the soup thickens. Remove the soup from the heat and stir in 1 direction to get a current going, then stop stirring. Slowly pour in the beaten eggs in a steady stream and watch it spin around and feather in the broth (it should be cooked almost immediately.) Garnish the hot and sour soup with chopped green onions and cilantro before serving.
Chinese Chicken Stock:
Put the chicken in a large stockpot and place over medium heat. Toss in the green onions, garlic, ginger, onion, and peppercorns. Pour about 3 quarts of cold water into the pot to cover the chicken by 1-inch. Simmer gently for 1 hour, uncovered, skimming off the foam on the surface periodically.
Carefully remove the chicken from the pot and pass the stock through a strainer lined with cheesecloth to remove the solids and excess fat. Cool the chicken stock to room temperature before storing in the refrigerator, or chill it down over ice first.