Duxelles

Duxelles is a French preparation of finely minced mushrooms, onions or shallots, and herbs such as thyme or parsley, sautéed in butter and reduced until the mixture forms a thick paste. Some versions add cream, madeira, or sherry. It is used as a filling in stuffings and sauces, most famously inside beef Wellington, as a garnish, or baked in raw pastry to make a savory tart. The preparation is credited to the seventeenth century French chef François Pierre La Varenne, who named it for his employer Nicolas Chalon du Blé, the marquis d'Uxelles, a French military marshal. Its flavor depends heavily on the mushrooms used, with wild porcini giving a far more intense result than white or brown mushrooms, and the chef Auguste Escoffier favored dehydrated mushrooms, which he believed sharpened the flavor while avoiding the excess moisture that could ruin a pastry. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/