[[Image:Avocado gratin.jpg|right|thumb|200px|[[Avocado]] gratin]]

'''Gratin''' refers to a preparation of thinly sliced potatoes or another ingredient and a cream sauce topped with a crust of [[brown (cooking)|browned]] [[breadcrumbs]] and butter often sprinkled with [[grated cheese]].<ref>The American Heritage® Dictionary of the English Language, Fourth Edition definition from Dictionary.com http://dictionary.reference.com/browse/gratin</ref> A gratin is prepared using a [[casserole]] with the sliced ingredients covered with [[Béchamel sauce]] or [[Mornay sauce]], topped with buttered breadcrumbs and/ or grated cheese. The dish is then baked or broiled to form a golden crust and then served in its baking dish.

The term is adapted from [[French cuisine]] and the name is from the [[French (language)]] word "gratter" meaning to "to scrape" as of the "scrapings" of bread or cheese. The technique predates the current name which did not appear in English until 1846 (''[[OED]]'', ''s.v.'' "gratin"; the French pronunciation, rather than "aw gratt'n", remains standard in English. The ''gratin'' signified the "upper crust" of Parisian society. Cooking '''''au gratin''''' is a technique rather than exclusively a preparation of potatoes (which is specifically a ''gratin dauphinois''): anything that can be sliced thin, layered with a cream sauce and baked is material for a gratin: fennel, leeks, crabmeat, celeriac, aubergines.

Gratin is also used to refer to a [[fireproof]] dish or [[casserole]] used to prepare gratins. The foods prepared in this way are refered to as gratiné, from the transitive verb form of the word for crust.

<ref>''Gratin'' from Epicurious.com's Food Dictionary http://www.epicurious.com/tools/fooddictionary/search?query=gratin</ref>

==Potato gratin==

Potatoes gratiné is one of the most common of gratins and is known by various names. In North America, the dish is referred to as ''scalloped potatoes''. (Note that the term scalloped originally referred to a seafood dish rather than to a [[scallop]]) <ref>Rombauer, Irma S. and Marion Rombauer Becker (1931 [1964]) ''The Joy of Cooking'', p 369. Indianapolis: Bobbs-Merrill. ISBN 0-452-25665-8.</ref>. In French-speaking Canada, the dish is referred to as ''pommes de terre au gratin''. Australians often refer to it simply as a ''potato bake''. The dish may also be known as ''gratin dauphinois'', ''pommes de terre dauphinoises'' or ''potatoes dauphinoises''.

Potatoes and onions au gratin with anchovies are as traditional in Swedish cuisine as they are in French,<ref>Julia Child, ''Mastering the Art of French Cooking'' I, 1961:154f "Gratin de pommes de terre aux anchois"</ref> where the dish is known as [[Janssons frestelse]].

==''Gratin dauphinois==

[[Image:Gratindauphinois.jpg|right|thumb|200px|Gratin dauphinois]]

The name ''gratin dauphinois'' refers to the [[Dauphiné]] region of France, where this method of preparing potatoes is a specialty. The ingredients composing a typical ''gratin dauphinois'' are thinly sliced and layered potatoes, milk (and/or cream or creme fraiche), cheese, garlic, salt and pepper. Eggs may sometimes be mixed with the milk/cream. ''Gratin savoyard'' is a variation found in the neighbouring region. Unlike ''gratin dauphinois'', it is made without milk, cream or eggs. Instead, it consists of alternating layers of sliced potatoes and [[Beaufort (cheese)| Beaufort cheese]] with bits of butter, and [[bouillon (broth)|bouillon]] is poured over before baking.<ref>''Larousse Gastronomique'' (2001)</ref>