Slice onions in rings and cut green peppers in large pieces. Sprinkle with garlic powder and brown in oil. Remove when brown and brown the meat. Do not overcook. Add onions and peppers to meat. Combine remaining ingredients and add to meat. Cook very slowly for about 20 minutes. Add Water chestnuts and bean sprouts, cook 5 minutes more. Serve over rice with chow mein noodles. Serves 4.