The rockfish, more commonly known as the striped bass, can grow up to six feet in length and migrates between fresh and salt water. Overfishing is a concern with rockfish, and as such, their meat is often expensive and available in small quantities. To cook rockfish fillets, you will need some fresh vegetables, everyday seasonings and approximately 30 minutes.

Preheat an oven to 350 degrees Fahrenheit.

Place the rockfish fillets in a baking dish in an even layer. Arrange them with 1/4 inch of space between each fillet. Pour the tomato sauce over the fillets.

Sprinkle the mushrooms, onion, celery, salt and pepper evenly over the top of the fish in the pan.

Cover the pan tightly with aluminum foil and bake for 30 minutes. Do not open the oven door as the fish bakes.

Remove the pan from the oven. Do not remove the aluminum foil; leave the pan to set for five minutes. Remove the aluminum foil and serve with the sauce from the pan over the top.