Drain pineapple, reserving syrup. Brown chicken in butter; Drain. Combine syrup with sherry, soy sauce, garlic and ginger. Pour over chicken. Cover, simmer 30 minutes, turning chicken once. Remove chicken. Add pineapple, bell pepper, celery, green onion and papaya to pan. Dissolve cornstarch in 1/2 cup water. Stir into pan. Bring to boil. When thickened, spoon over chicken.