Genoese sauce

Ingredients: Onion, butter, Burgundy, mushrooms, truffles, parsley, bay leaf, Espagnole sauce (No.1), blond of veal, essence of fish, anchovy butter, crayfish or lobster butter.

Cut up a small onion and fry it in butter, add a glass of Burgundy, some cuttings of mushrooms and truffles, a pinch of chopped parsley and half a bay leaf. Reduce half. In another saucepan put two cups of Espagnole sauce, one cup of veal stock, and a tablespoonful of essence of fish, reduce one-third and add it to the other saucepan, skim off all the grease, boil for a few minutes, and pass through a sieve. Then stir it over the fire, and add half a teaspoonful of crayfish and half of anchovy butter.

See also: Wikipedia Cookbook.

Source: The Cook's Decameron: A Study In Taste, Containing Over Two Hundred Recipes For Italian Dishes from a project that puts out-of-copyright texts into the public domain. This is from a *very* old source, and reflects the cooking at the turn of the last century. Update as necessary.