Marinate chicken breasts 30 min. in salt, pepper, cornstarch,sherry & egg. Heat wok hot & dry. Add oil. When it's just beginning to smoke, add chicken,green pepper & water chestnuts, stirring 1-2 min. Drain through colander or sieve, reserving 2-3 tbs. oil. Return the reserved oil to wok & add Imperial Sauce & hoisin sauce. Cook 1-2 min. or until thickened slightly. Add nuts,chicken & vegetables, stirring everything together until well coated w/ sauce. Serve. Note: Hoisin sauce is pre-packaged, found in Chinese specialty stores. Made from soybeans, flour,sugar,garlic & chili peppers, it is reddish-brown in color & is creamy & sweet. If it's too thick to spread, thin w/ some sesame oil.