Foie Gras en Terrine

Foie gras — literally "fat liver" — descends from one of the oldest documented luxuries in cooking. The deliberate force-feeding of geese to fatten their livers is recorded in ancient Egypt as early as around 2500 BC, where a bas-relief in the tomb of Mereruka at Saqqara shows workers overfeeding the birds. The Romans turned it into a named delicacy, fattening geese on dried figs and calling the result iecur ficatum, "fig liver"; it is from ficatum, the fig word, that the modern Romance terms for liver descend — Italian fegato, Spanish hígado and French foie itself. The terrine tradition belongs to the gastronomic Southwest, where roughly 90% of French production is concentrated across the Périgord, Gascony and the rest of Aquitaine, alongside Alsace in the east. France protects the regional product under the PGI "Canard à foie gras du Sud-Ouest," which covers Chalosse, Gascogne, the Gers, the Landes, Périgord and Quercy. Once a goose preparation, foie gras is now overwhelmingly made from duck (canard): ducks accounted for about 95% of production by 2014.

Served cold, a slice should melt the instant it meets the warmth of the tongue, dissolving into a buttery, faintly sweet film of fat rather than chewing like meat. The mi-cuit texture is the whole point: silkier, creamier and looser than a fully-cooked, firmer bloc, yet set enough to cut clean against the blade. The flavor is rich and mineral, with the liver's deep iron tempered by the Armagnac and the salt-sugar cure, and it wants the contrast of crisp toasted brioche and a cold sip of sweet wine.

The craft turns on a narrow temperature window. Foie gras is mostly fat, and that fat melts low — differential-scanning-calorimetry studies of duck fatty liver put its melting across roughly -20°C up to about 40°C, with the main fatty acid, oleic acid, melting near 13°C. Cook the liver too hot and the fat simply liquefies and weeps out, leaving a shrunken, greasy remnant. So the terrine is brought only to a mi-cuit core temperature of about 45-50°C: warm enough to set the liver's proteins and pasteurize it, but below the point at which all the fat renders away. That is what "mi-cuit" means — half-cooked, pasteurized but not fully cooked, as opposed to a fully cooked terrine taken higher (around 60°C). Deveining first removes the tough vessels that would otherwise bleed and toughen; the salt and small dose of sugar season and lightly cure the flesh; and weighting the cooled terrine compacts it and pushes the rendered fat to the surface, where it solidifies into a sealing cap that protects the liver as it rests and the flavor matures over a few days' chilling.