Knead together in a saucepan four ounces of butter with one and a half ounces of fresh bread-crumbs, add the juice of one lemon; two spoonfuls of meat glaze (No. 401), some nutmeg and mignonette. Set this on a moderate fire, and stir the preparation without letting it boil; just when ready to serve, add one tablespoonful of chopped parsley, dilute it with stock (No. 423); see that the sauce is not too thick.
A butter-and-crumb sauce thickened without roux, from Ranhofer's The Epicurean. It stands or falls on temperature control: the butter is an emulsion held together by the crumbs, and boiling will break it.
Charles Ranhofer, chef at Delmonico's in New York, published The Epicurean in 1894 as a nearly complete transcription of the French professional repertoire as it was practised in an American grand restaurant, and the hot sauce chapter runs to well over a hundred numbered entries cross-referenced to one another, as this one is. Names like "a la Lithuanienne" belong to a nineteenth-century French convention of tagging sauces with national or regional epithets that often signalled little more than a characteristic ingredient or a compliment to a patron; the sour-and-buttery profile here, lemon juice with a crumb thickening, does echo the butter-and-crumb finishes common across northern and eastern European cooking, though the connection is traditional rather than documented. What is notable technically is the thickening: no flour, no roux, just soft crumbs swelling in butter and stock, an older method that predates the codified mother sauces and survived in kitchens because it produces a lighter, more fragile sauce that must be served the moment it is made.