Place wood ears and lily buds in separate bowls; cover with hot water. Let soak 30 minutes; drain. Pinch out hard knobs from center of wood ears and discard. Squeeze out excess water.
Cut wood ears into thin strips. (If using mushrooms, cut off and discard stems; cut caps into thin slices.) Cut off and discard hard tips from lily buds; tie each bud onto itself to make a knot in the middle.
Cut bamboo shoots into matchstick pieces.
Cut chicken crosswise into thin slices; sprinkle with sherry. Let stand 15 minutes.
Heat chicken broth in large saucepan over high heat to boiling. Add wood ears, lily buds, chicken and bamboo shoots. Reduce heat to low; simmer, uncovered, 3 minutes. Add bean curd, vinegar, soy sauce and white pepper; simmer 3 minutes.
Blend cornstarch and water in small cup until smooth; stir into soup. Cook, stirring constantly, until slightly thickened. Turn off heat. Stirring constantly, slowly pour egg into soup. Stir in sesame oil and onions. Ladle into soup bowls; sprinkle with coriander.
Serve immediately. Makes 8 to 12 servings.