1. Prepare rice according to package directions. Set aside.
2. Preheat oven to 375°F.
3. In a medium bowl, mix tomato sauce, chili powder, garlic & pepper.
4. Lightly coat a large glass baking dish with cooking spray. Place fish in baking dish; top with onions & peppers. Pour sauce mixture over fish & vegetables.
5. Cover dish with foil & bake 30 minutes, or until fish flakes with a fork.