Demi-glace (from French for "half-iced" for the French word "glace" when used in reference to a sauce means "glaze" or "icing". It can also refer to "ice-cream")(or Spanish Sauce) is a type of brown sauce. It is traditionally made by combining equal parts of beef or veal stock and espagnole, one of the five "mother sauces" of classical French cuisine, which is then simmered and reduced by half. The result is a thick, rich sauce. While the demi-glace is suited for meats and other rich dishes, it is more commonly used as a base for other rich sauces and soups.The basic recipe for demi-glace is provided by the French chef Escoffier, who is often considered to have established the method of French cooking as well as codified many of the standard French receipes. Although many recipes for demi-glace give the preparation for the espagnole first, and then the recipe for the brown stock, preparation should actually proceed in the reverse. A basic brown stock should be prepared, beef or veal, and, when completed, left on the heat to remain very warm. At this point, the espagnole is prepared, and when it is finished, the brown stock is added in equal portions to the espagnole.Due to the considerable effort involved in making the traditional demi-glace, it is not uncommon to substitute a simple reduction of veal stock for a true demi-glace, or to create a simulated version (Julia Child referred to this as a "semi-demi-glace"). However, even today, many chefs who prepare French haute cuisine use a demi-glace prepared in their own kitchen. Concentrates and mixes are available, mostly to professional kitchens, as a way of avoiding the labor inherent in preparing the sauce. These vary in quality.