Sauce Robert is a brown mustard sauce and one of the small sauces, or compound sauces, derived from the Classic French demi glace, one of the mother sauces in French cuisine. Sauce Robert is made from chopped onions cooked in butter without color, a reduction of white wine, pepper, an addition of demi-glace and is finished with mustard. It is best suited to pork, especially grilled pork, and meats.