Ham-and-Potato Casserole

Combine potatoes, carrots, celery and water in a microwave-safe bowl. Microwave on HIGH for 7 to 8 minutes, or until tender-crisp, stirring once. Drain. In a medium bowl combine ham, green bell pepper, onion and butter in a bowl. Microwave on HIGH for 3 to 4 minutes, stirring once. Combine the potato mixture and the ham mixture; set aside. In another separate bowl microwave butter on HIGH for 1 minute, or until melted. Stir in flour and milk, stirring until smooth. Microwave on HIGH for 3 to 5 minutes, or until thick and bubbly, stirring twice. Add cheddar cheese, salt and pepper; stir until the cheese melts. Pour the cheese sauce over the ham mixture and sprinkle with crushed crackers. Microwave on HIGH for 8 to 9 minutes, turning once. Serve immediately.