Pound half a pound of frangipane panada (No. 120) with six ounces of butter and half a pound of raw and very white fat livers; season with salt, pepper and nutmeg and when the whole is well pounded, strain through a sieve, then add six raw egg-yolks and two well beaten whites while continuing to work the forcemeat.
This is a component preparation, not a finished dish: a rich foie gras farce meant to be piped into quenelles, used to stuff poultry and game, or spread in timbales and pâté moulds, then cooked. Ranhofer assumes you have the panada from No. 120 already made and chilled.
Charles Ranhofer spent more than thirty years as chef at Delmonico's in New York, and The Epicurean (1894) is essentially his kitchen's working manual, organised so that a dozen elaborate dishes can call back to one numbered base preparation like this. Farce is simply the French for a pounded, bound stuffing — the same word behind English "forcemeat" — and the panada-and-egg method he uses here is the classical way of giving a delicate meat enough body to hold its shape when poached as a quenelle. Foie gras itself reached American luxury kitchens largely as an imported product from Strasbourg and the southwest of France, where the fattening of geese is generally traced back to Roman and, before that, Egyptian practice. That a book aimed at professional cooks lists a foie gras forcemeat among its elementary methods, alongside fish and game farces, says a good deal about the register at which Delmonico's operated.