duxelles

Etymology
+ Uxelles; the dish is said to have been named for Nicolas Chalon du Blé, marquis d'Uxelles, maréchal de France.

Noun

 * 1)  A finely chopped mixture of mushrooms, onions, shallots and herbs sautéed in butter and reduced to a paste, used in stuffings and sauces (as in beef Wellington) or as a garnish.