Mirepoix derives its name , as many other elements of French cuisine do , from the patron of the chef who established it , in this case one of the house of LÃ vis , seigneurs of Mirepoix since the eleventh century and a famous name in Languedoc . The particular member of the house of LÃ vis whose chef is credited by the Dictionnaire de l'Acad Ã mie franÃ aise with giving a name to an old technique is Charles-Pierre-Gaston FranÃ ois de LÃ vis , duc de LÃ vis-Mirepoix ( 1699-1757 ) , marÃ chal de France and ambassador of Louis XV . Though the cooking technique is probably older , the term mirepoix dates from the eighteenth century and derives , as do many other appellations in French cuisine , from the aristocratic employer of the cook credited with establishing and stabilizing it : in this case , Charles-Pierre-Gaston FranÃ ois de LÃ vis , duc de LÃ vis-Mirepoix ( 1699 â `` 1757 ) , French field marshal and ambassador and a member of the noble family of LÃ vis , lords of Mirepoix in Languedoc since the eleventh century .