Preheat oven to 400°.
Place fish in a 13 x 9-inch baking dish coated with cooking spray.
Heat oil in a large nonstick skillet over medium-high heat. Add onion; saute 3 minutes. Add cumin and garlic; saute 1 1/2 minutes. Add water and remaining ingredients; bring to a boil. Reduce heat; simmer 3 minutes or until slightly thick. Pour tomato mixture over fish.
Bake at 400° for 20 minutes or until fish flakes easily when tested with a fork.