To cook fish wrapped in aluminum foil, first season the fish with your choice of herbs, spices, and a little oil. Place the seasoned fish on a large piece of aluminum foil. Add any vegetables you like, such as lemon slices, garlic, or herbs, and fold the foil to seal the fish and vegetables inside, creating a pouch. Place the foil packet on a baking sheet and bake in a preheated oven at 400掳F (200掳C) for about 15-20 minutes, or until the fish flakes easily with a fork. Be sure to let the packet cool slightly before opening to avoid steam burns.