In a 3 quart microwavesafe casserole, combine onion, green pepper, garlic and water. Microcook, covered, on 100% power (High) for 4 to 5 minutes or until onion and pepper are tender; drain. Stir in lima beans, undrained butter beans, kidney beans, garbanzo beans, water chestnuts, ketchup, brown sugar, mustard, Worcestershire sauce and pepper. Cook, covered, on High for 10 to 12 minutes (low watt oven, 20 to 22 minutes), stirring after every 5 minutes.