Despite its name, Espagnole Sauce (“Spanish Sauce”) is not Spanish, but rather a brown sauce in classical French cooking used as the basis for many other sauces, such as Poivrade Sauce.
There are three versions of it.
Sauce espagnole graisse
In a frying pan, soften up a mirepoix along with lean diced bacon in lard. Add white wine, bay leaf and thyme. Add the mixture to a brown stock thickened with a roux. Simmer for 2 1/2 hours, skimming all the while. Strain, and allow the sauce to cool and sit overnight. The next day, reheat it, and add more stock and some tomato purée. Simmer for a further hour, skimming all the while. Then strain.
“Graisse” means “fat.”
Sauce espagnole maigre
The mirepoix is cooked in butter instead of lard, plus mushroom skins are added. Fish stock is used instead of brown stock.
“Maigre” means “thin.”
Carême’s version of Sauce espagnole
This is how the chef Antoine Carême made Espagnole Sauce. His instructions can make the other two seem like fast-food versions.
Put a few inches of stock in a pot and bring to a simmer. Add 2 slices of Bayonne ham, 1 noix of veal and 2 partridges. Simmer until the stock is reduced to just a coating on the pan.
Slash the veal with a knife so that juices can flow out, then put the pot back on very low heat for about an hour. Remove the pot from the heat and allow to cool. Then fill the pot with a clear stock, bring it to a boil, and skim it.
Make a blond roux and cook it a bit. Add 2 ladles of the stock to the roux, whisk, then add the roux mixture back to the main stock pot, along with parsley, green onions, bay leaf, thyme, chives and mushroom skins and mushroom stems. Simmer for an hour and a half, and skim the surface twice for fat. Then strain through a cloth.
By 1960, Larousse Gastronomique noted that custom had simplified Carême’s version, with the noix of veal being just a shoulder of veal, and the partridges having flown the recipe altogether.