Custard is a preparation involving the use of milk or cream cooked with egg yolk to thicken. In some cases, flour, corn starch, or gelatin are also used. The consistency of the custard varies depending on how it is used – if it is crème anglaise, the custard is thin, but if it is for crème pâtissière used to fill éclairs, the custard should be thick. A common use of custard is as a sweet dessert containing vanilla and sugar, although there is also custard in savory foods like quiche, a French tart.
The practice of making custard tarts date back to the Middle Ages. The word ‘custard’ originates from the French word ‘croustade’ (which was derived from the Italian word crostata, which is from the Latin crustāre), pertaining to the crust of the tart. The 14th-century collection of recipes entitled The Forme of Cury made mention of two custard dishes – Crustardes of flessh and Crustade. Custards are commonly served in the Northern United States during the Fourth of July celebration.