Soak wood ears and lily buds in 3 cups hot water 15 minutes to soften. Remove stems from softened wood ears. Shred wood ears with a cleaver. Slice pork into thin strips. Use a cleaver to chop strips into shreds. Combine marinade ingredients in a small bowl. Add pork shreds; mix well. Let stand 15 minutes. Combine chicken broth and salt in a medium saucepan. Bring to a boil over high heat; reduce heat to medium. Add mushrooms, water chestnuts, bamboo shoots, wood ears and lily buds to broth. Simmer 3 to 4 minutes. Add pork shreds with marinade and bean curd. Bring to a boil. Add worcestershire sauce and vinegar, if desired. Dissolve cornstarch in 5 tablespoons water to make a paste. Slowly stir into soup. Cook over medium heat until soup thickens slightly. Stir egg into soup. Add black pepper, white pepper and sesame oil.