Cover mushrooms with warm water, let stand for 30 minutes, then drain. Cut off and discard stems; squeeze mushrooms dry, thinly slice and set aside. In a bowl, combine soy, cornstarch, sherry, water and pepper. Add chicken and toss to coat, then stir in 1 1/2 t of the oil and let stand for fifteen minutes to marinate. Prepare cooking sauce mix together wateaar, sherry, oyster sauce, sugar, sesame oil and cornstarch and set aside. Place a wok or wide frying pan over high heat. When pan is hot, add 2 T of the oil. When oil begins to heat, add garlic and stir once. Add chicken and stir-fry until chicken is opaque (about 3 minutes). Remove chicken from pan. Add remaining 1 T oil to pan. When oil is hot, add mushrooms and bamboo shoots. Stir-fry for one minutes, adding a few drops water if pan appears dry. Add snow peas and stir-fry for 1 1/2 minutes, adding a few drops more water if pan appearas dry. Return chicken to pan. Stir cooking sauce, add to pan, and cook, stirrin guntil sauce bubbles and thickens. Variations: Cashew or Almond Chicken first toast 1/2 c cashews or blanched almonds in 1 T salad oil over medium-low heat until golden; remove from pan and set aside. Stir in nuts just before serving.