The CWI Cookbook

 1/2 c. drawn (clarified) butter
1/2 c. minced parsley
1 lemon
Cayenne pepper
Salt

Draw the butter; boil the parsley three minutes; take it out and lay in cold water five minutes, to cool; chop and stir into the butter; squeeze in the lemon-juice, the pepper and salt; beat hard with an egg-whip, return to the fire, and boil up once. This is a “stock” sauce, being suitable for so many dishes, roast or boiled.

From Common Sense in the Household by Marion Harland, New York, 1871

Comment: Few of the sauces we commonly take for granted today– tartar, barbeque, even ketchup and mustard–were available prepackaged and bottled in stores. (The notable exception being Worcestershire, which the Lea & Perrins company has had in commercial production since 1837!) and so had to be produced at home if one aspired to a fancy or impress-the-boss sort of meal. “Maitre d’Hotel Sauce” is probably the simplest of the lot.