Cut meat in 1-inch strips, and cook 5 minutes in frying pan in 2 tablespoons chicken or other fat. Cut celery in thin slices crosswise, add onion peeled and cut in thin slices, mushroom caps peeled and sliced, Chinese water chestnuts peeled and sliced. Cook vegetables 5 minutes in 2 tablespoons chicken fat or butter. Add bean sprouts, bamboo shoots cut in diamond-shaped pieces, Soyu sauce, chicken stock or water and the cooked meat, and simmer gently until bean sprouts and meat are thoroughly cooked. Season with salt and pepper.