1 jar spaghetti sauce
2 lbs. haddock or cod
1 med. onion, sliced
1 stalk celery, diced
2 tbsp. olive oil

Preheat oven to 325 degrees. Spread 1/2 cup spaghetti sauce on bottom of baking dish. Arrange fish in the dish. Saute onion and celery in oil; spread on top of fish. Cover with remaining sauce. Cover and bake for 40 minutes.