Mirepoix
Traditionally, the ratio for mirepoix is 2:1:1 of onions, celery, and carrots. The ratio for bones to mirepoix for stock is 10:1. When making a white stock, or fond blanc, parsnips are used instead of carrots to maintain the pale color.
Mirepoix derives its name, as many other elements of French cuisine do,[1] from the patron of the chef who established it, in this case one of the house of Lévis, seigneurs of Mirepoix since the eleventh century, a famous name in Languedoc.[2] The particular member of the house of Lévis whose chef is credited by the Dictionnaire de l'Académie française with giving a name to an old technique is Charles-Pierre-Gaston François de Lévis, duc de Lévis-Mirepoix (1699-1757), maréchal de France and ambassador of Louis XV.[3]