Grouper is a popular fish among the health-conscious, possessing a lovely, mild flavor which lends itself to a variety of preparations. Oven-roasting is a great way to prepare grouper while keeping the calories light. Wrap it in foil to keep the lean fish moist during cooking. Add your favorite seasonings to the grouper fillets before you wrap them up and put them in the oven, and you'll wind up with a moist, flavorful fish dish.
Preheat your oven to 400 degrees Fahrenheit.
Tear off enough aluminum foil to individually cover each grouper fillet. Lightly grease the center of each piece of foil with olive oil or a cooking spray.
Place the grouper fillets on each piece of foil, and add desired seasonings or sauces. Try simply seasoning with salt and pepper, or prepare a simple tomato sauce with fresh herbs. Carefully fold the foil to create a packet around each fillet, leaving space above the fillets to create a tent. Seal the packet closed by pinching the seams together so that steam doesn't escape while baking.
Place the foil packets on a baking sheet, and slide them into the oven. A general rule for cooking fish is to measure the flesh at its thickest point and cook 8 to 10 minutes per inch, 4 to 5 minutes per half-inch. Add an additional 5 minutes for fish cooked in foil.
Cook the grouper fillets until they are opaque in appearance and flake easily with a fork. Remove from foil, and serve with fresh lemon wedges, if desired.