Steps

1. In a bowl, combine the chicken with the salt, cornstarch, sugar, and soy sauce, stirring to coat evenly. Marinate for 30 minutes.
2. Soak the wood ears in warm water for 30 minutes. Drain, rinse, and cut off and discard the hard ends, then shred the wood ears finely.
3. Rinse and soak the dried black mushrooms in hot water for 30 minutes or until the caps are soft. Cut off and discard the stems. Cut the mushroom caps into a fine julienne (less than ¼ inch wide).
4. Clean and remove both ends of the green onion (if using). Make several vertical cuts and then cut crosswise into 2-inch pieces, resulting in fine shreds. Set aside for garnishing the finished soup.
5. In a large pot, combine the soup stock, cooking wine, ginger, chile sauce, and vinegar with 1½ quarts of water and bring to a boil. Add the carrots, bamboo shoots, mushrooms, wood ears, and tofu, and return to a boil. Add the chicken and shrimp, and cook until they turn opaque. Remove from the heat and stir in the egg and ground white pepper.
6. In a small bowl, combine the thickening-mixture ingredients and gradually stir into the hot soup, adding a little at a time until the soup reaches the desired thickness. Serve hot, garnished with the shredded green onion.