Clean the fish and make some cuts diagonally on both side . Gently rub inside and out with 2 tablespoons of garlic oil, salt and pepper to taste.
Fill the fish with slices of lemon butter, and with branches of thyme and oregano .
Preheat grill to medium temperature and oil the grates with garlic oil so that the fish will not stick. By giving back to the fish re-grease the grates and cook until lightly browned skin. Depending on the size of the fish should cook about 10-15 minutes on each side. Serve on a bed of lettuce.