4 dried Chinese mushrooms, 1 to 1 1/2 inches in diameter
2 sq., 3 inches each, fresh Chinese bean curd, about 1/2-inch thick
1/2 c. canned bamboo shoots
1/4 lb. boneless pork
1 qt. chicken stock, fresh or canned
1 tsp. salt
1 tbsp. soy sauce
1/4 tsp. ground white pepper
2 tbsp. white vinegar
2 tbsp. cornstarch mixed with 3 tbsp. cold water
1 egg, lightly beaten
2 tsp. sesame seed oil
1 scallion, including the green top, finely chopped

Prepare ahead: In a small bowl, cover the mushrooms with 1/2 cup of warm water and let them soak for 30 minutes. Discard the water. With a cleaver or knife, cut away and discard the tough stems of the mushrooms, and shred the caps by placing one at a time on a chopping board. Cut them horizontally into paper-thin slices, and then into thin strips.

Drain the pieces of bamboo shoot and bean curd, and rinse them in cold water. Shred them as fine as the mushrooms.

With a cleaver or sharp knife, trim the pork of all fat. Then shred it, too, by slicing the meat as thin as possible and cutting the slices into narrow strips, about 1 1/2 to 2 inches long.

Have the above ingredients, stock, salt, soy sauce, pepper, vinegar, cornstarch mixture, egg, sesame seed oil and scallions within easy reach.

To Cook: Combine in a heavy 3-quart saucepan the stock, salt, soy sauce, mushrooms, bamboo shoots and pork. Bring to a boil over high heat, then immediately reduce the heat to low. Cover the pan and simmer for 3 minutes.

Drop in the bean curd, and the pepper and vinegar. Bring to a boil again. Give the cornstarch mixture a stir to recombine it and pour it into the soup. Stir for a few seconds until the soup thickens, then slowly pour in the beaten egg, stirring gently all the while. Remove the soup from the heat and ladle it into a tureen or serving bowl. Stir in the sesame-seed oil and sprinkle the top with scallions. Serve at once.