Gratin is a type of a French cuisine. It is known as a type of casserole which is covered with baked or boiled bread crumbs along cheese or butter. Mostly potatoes are used while making gratins, however they are not a necessity. People often have the wrong notion that while making gratin it is essential to make it in cheese. While on the other hand the fact remains that the traditional French gratin is made more often in Béchamel sauce.