dux·elles 
(dük-sĕl dk-, dək-)
(dük-sĕl dk-, dək-)n.
A mixture of minced mushrooms, shallots, and often herbs, sautéed in butter and used in various sauces and stuffings or as a garnish.
[French, from earlier à la duxelle, in a mushroom sauce, probably after Louis Chalon du Blé, marquis d'Uxelles (1619-1658), French nobleman and employer of François Pierre de la Varenne (1618-1678), French chef whose influential cookbook introduced the abundant use of mushrooms in haute cuisine.]