Directions
Cover the dried mushrooms with warm water and allow to soak for about 20 minutes. Drain, remove stems and slice into thin strips.
Bring the chicken stock to a boil in a pot or deep sauce pan. Stir in mushrooms, pork and bamboo shoots and simmer for about 2 minutes. Then add the tofu, vinegar, soy sauce, chili garlic sauce, white pepper, and sugar and simmer for 2 more minutes. Then add corn starch mixture, and boil for about 1 more minute.
Stirring the soup briskly, very slowly pour in the beaten egg. This will form whispy threads of cooked egg in the soup. Serve garnished with the scallions.