Supreme sauce

Ingredients: White sauce, fowl stock, butter.

Put three-quarters of a pint of white sauce into a saucepan, and when it is nearly boiling add half a cup of concentrated fowl stock. Reduce until the sauce is quite thick, and when about to serve pass it through a tamis into a bain-marie and add two tablespoonsful of cream.

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.