In bowl, mix pork with Marinade; set aside. Bring chicken broth to boil. Add pork, tofu, bamboo shoots, carrots, mushrooms and celery. Return to boil, stirring gently to separate pork shreds. Stir in soy sauce, vinegar and pepper. Taste soup and adjust seasonings. Slowly stir enough cornstarch paste into simmering soup to thicken lightly. Slowly drizzle eggs into broth in thin stream. When egg curds set, gently stir in sesame oil. Garnish each serving with green onions.
To make Marinade: In bowl, lightly beat 1 egg. Mix in 1 tablespoon each soy sauce, dry sherry, cornstarch and vegetable oil; cover and refrigerate unless using immediately.