a sauce, a combination of mushrooms, parsley, and shalots (small onions), which are chopped together finely and used for flavouring.
Duxelles is a finely chopped mixture of mushrooms, onions, shallots and herbs sautéed in butter. It is a basic preparation used in stuffings and sauces (notably, Beef Wellington). It is said to have been created by the 17th-century French chef François Pierre La Varenne (1615–1678) and to have been named after his employer, Nicolas Chalon du Blé, marquis d'Uxelles, maréchal de France.