The etymology of gratin is from the French language words gratter, meaning "to scrape" or "to grate" (for example, "scrapings" of bread or cheese), and gratiné, from the transitive verb form of the word for crust or skin [REF].
In addition to the well-known potato dishes such as Gratin dauphinois, cooking au gratin is a widely used cooking technique in the preparation of numerous dishes including many meat, fish, vegetable and pasta dishes, fennel, leeks, crab meat, celeriac and aubergines (eggplant) [REF].