In cooking, espagnole sauce is one of the mother sauces that are the basis of sauce-making in classic French cooking. Auguste Escoffier codified the recipe in the late 19th century, which is still followed today. Espagnole has a strong, even somewhat unpleasant taste and is not itself used directly on food. As a mother sauce, however, it then serves as the starting point for many derivative sauces. Examples include, but are not limited to, Sauce Africaine, Sauce Bigarade, Sauce Bouguignonne, Sauce aux Champignons, Sauce Charcutiere, Sauce Chasseur, and Sauce Chevreuil. There are hundreds of others in the classic French repertoire.
The basic method of making espagnole is to prepare a very dark brown roux, to which are added several gallons of veal stock or water, along with 20 or 30 pounds of browned bones, pieces of beef, many pounds of vegetables, and various seasonings. This blend is allowed to slowly reduce while being frequently skimmed. The classical recipe calls for additional veal stock to be added as the liquid gradually reduces but today water is generally used instead. Tomato sauce is added towards the end of the process, and the sauce is further reduced.
A typical espagnole recipe takes many hours or even several days to make, and produces four to five quarts of sauce. In most recipes, however, one cup of espagnole is more than enough, so that the basic recipe will yield enough sauce for 16 to 20 meals. Frozen in small quantities, espagnole will keep practically indefinitely.