1/2 c. sliced celery
1/2 c. chopped green pepper
1 sm. onion, sliced thin
1 (8 oz.) can tomato sauce
1/2 tsp. salt
1/2 tsp. chili powder
1/4 tsp. garlic powder
1/4 tsp. dried oregano leaves
1/4 tsp. dried thyme leaves
1 lb. fish fillets

Combine celery, green pepper, and onion in 8 inch square microwave safe baking dish. Cover with plastic wrap. Microwave (high) 2 1/2 to 3 minutes or until just about tender. Add remaining ingredients except fillets. Cover. Microwave (high) 2 to 3 minutes or until mixture boils and flavors are blended. Push vegetables to side of dish; arrange fillets in dish. Spoon vegetables and sauce over fish. Cover. Microwave (high) 4 to 4 1/2 minutes or until fish flakes apart easily, rotating dish once.
 

Source: http://www.nancys-kitchen.com