Filets of fish
Salt
Chopped onion
1 (8 oz.) jar spaghetti sauce with mushrooms
Mozzarella cheese

Layer filets of fish in a glass baking dish that has been sprayed with Pam. Sprinkle with salt and chopped onion. Cover the fish with spaghetti sauce. Bake 25 minutes in 350 degree oven. Take out of oven; sprinkle with cheese over top. Return to oven until cheese melts about 5 minutes.