Like any French mother sauce, espagnole is not meant to be served as is. Rather, it's a base for any number of other, more complex sauces.
Why you need to learn this
As Americans, we don't think of "sauce" so much as we think of "gravy." But French mother sauces — including veloute, hollandaise, bechamel, and tomato — are the sauces from which all other sauces are derived.
The steps you take
In a nutshell, espagnole is a thickened, flavor-enhanced brown stock. Naturally, you can imagine that this sauce will taste a lot better with homemade brown stock, whether it's beef, veal, poultry or what have you.
Still, homemade stock is an uncommon luxury for most of us, and packaged stock or broth will have to do. Fortunately, nearly 50 years ago the blessed Julia Child advised us how to doctor up packaged broth to make it taste closer to the real thing: For every pint of packaged broth, add 3 tablespoons chopped carrots, celery and onion along with a little tomato paste, bay leaf, fresh parsley and half a teaspoon of thyme. Simmer this for about half an hour with a generous splash of good red wine, and you'll have something worthy of your espagnole.
Like two of its fellow mother sauces, bechamel and veloute, espagnole is thickened with roux, an equal amount by weight of flour and butter cooked to varying degrees. Because we're working with brown stock, espagnole requires a brown roux, which means you'll have to be patient while your roux cooks until it becomes a rich, nutty brown. (Be sure to stir the roux frequently to ensure even cooking and to prevent it from burning. Using a saucepan or Dutch oven with a heavy bottom will also help scorching.)
Once you have espagnole sauce …
In classical French cuisine, espagnole was combined with an equal amount of brown stock and reduced by half to produce the elixir known as demi-glace. Modern demi-glace is more often simply brown veal stock reduced by half. (If, by chance, you're making your own veal stock, it's best to reduce it by about three-fourths, at which point it becomes "glace de viande" and is best stored in ice-cube trays. It'll keep forever and will save you the trouble of making espagnole every time you want a brown sauce.)
As you can guess, the differences among espagnole, classical demi-glace and modern demi-glace are largely a matter of degree. Today's home chef can produce any of the small brown sauces using any of them. Here are a few of the small brown sauces that are based on 2 cups of brown sauce, whether espagnole or demi-glace.
Bordelaise: Reduce 1 cup red wine with a minced shallot, a bay leaf and a pinch of thyme to 2 ounces. Add brown sauce, and simmer 10 minutes. Strain through a fine sieve and whisk in 2 tablespoons whole butter. Garnish with optional poached bone marrow.
Robert: Saute half a diced onion in butter, then add a cup of white wine and reduce to 2 ounces. Add brown sauce and a teaspoon of Dijon mustard. Strain through a fine chinois and whisk in 2 tablespoons whole butter.
Chasseur: Saute several sliced mushrooms with a minced shallot in butter. Add cup of white wine and reduce to 2 ounces. Add brown stock and peeled, seeded and chopped tomato. Simmer 5 minutes; do not strain.
Prep: 20 minutesCook: 1 hour, 25 minutesMakes: 1 quart
2 ounces butter
1 onion, diced
1/2 carrot, diced
1 celery rib, diced
1/3 cup flour
2 tablespoons tomato paste
1 quart brown stock or canned beef broth
1 bay leaf
1/2 teaspoon dried thyme
1/4 bunch parsley
Melt butter over medium heat in a saucepan. When foam subsides, turn heat to medium high; add onion, carrot and celery. Cook, stirring often, until lightly browned, about 8 minutes. Add flour; cook, stirring often, until dark brown, 8-12 minutes.
Add tomato paste, brown stock or beef broth and bay leaf, thyme and parsley. Turn heat to high; heat to a boil. Reduce heat to low; simmer 1 hour, skimming occasionally. Strain sauce through a fine sieve, pressing on solids.
Per tablespoon: 11 calories, 61% of calories from fat, 1 g fat, 0 g saturated fat, 2 mg cholesterol, 1 g carbohydrates, 0 g protein, 40 mg sodium, 0 g fiber