Demi-glace

Demi-glace is the classic French "mother-derived" brown sauce: equal parts sauce espagnole and rich brown veal or beef stock, simmered and skimmed until reduced by about half to a glossy, almost syrupy glaze that coats the back of a spoon. Deeply meaty, roasted and intensely umami-rich, it carries a layered depth of caramelised bones, tomato, red wine, herbs and root vegetables. It is the foundation of countless restaurant pan sauces — sauce au poivre, bordelaise, chasseur, Périgueux — and one of the most labour-intensive building blocks in the classical repertoire.