Hot and Sour Soup

4 dried Chinese mushrooms
1 tablespoon vegetable oil
2 half inch ginger root slices, minced
1/2 cup bamboo shoots, sliced
2 cups chicken stock
1 cup pork, sliced thinly
2 tablespoons soy sauce
1 cake tofu, cubed
1/2 teaspoon white pepper
2 tablespoons rice wine vinegar
2 tablespoons cornstarch
1 egg, beaten
1 tablespoon fresh coriander leaf , chopped
1 tablespoon scallions, chopped
1 teaspoon sesame oil

Soak mushrooms in hot water for 30 minutes. Drain, remove and discard stems and shred caps. Heat oil in heavy duty saucepan, add shredded mushroom caps and ginger and stir over moderately high heat for one minute. Add bamboo shoots and stir for an additional minute. Add chicken stock, pork slices, and soy sauce. Bring to a boil and simmer ten minutes. Add tofu and cook three minutes more. Dissolve cornstarch in 1/4 cup cold water. Add, with pepper and vinegar, to soup. Cook until mixture thickens and clears. Turn off heat and drizzle beaten egg over top. Stir. When egg sets, serve, garnishing with chopped scallions, coriander leaves, and sesame oil to taste.