how long do you grill tilapia in foil
1 If baking the fish, transfer it to a 9x13 inch baking dish along with the olive oil, garlic, and onion. 2  Sprinkle the fish with the cayenne or white pepper. 3  If you are grilling the fish, wrap the fish and oil, garlic, onion, and pepper in aluminum foil. 4  Bake at 350 degrees F (175 degrees F) for 30 minutes.