The French grade and classify foie gras with a manic fervor that defies comprehension by us foreign infidels. Here is a brief key to the code for French foie gras:
PÂTÉ DE FOIE GRAS: Often includes pork or veal liver, pork, chicken, or ham as well as scraps of duck or goose liver.
MOUSSE DE FOIE GRAS: Made by pureeing the trimmings from lobes of genuine foie gras.
BLOC DE FOIE GRAS: Reconstituted from smaller pieces of foie gras and pureed.
FOIE GRAS: Large pieces of the lobe, pressed together.
FOIE GRAS ENTIER: By far the most expensive variety—a whole lobe, or a single piece cut from one.
FOIE GRAS CRU: Raw. You buy it, take it home, and cook it right away. This is what the chefs of the great restaurants start with.
FOIE GRAS FRAIS: Lightly cooked, but neither sterilized nor pasteurized; it is also known as mi-cuit (half cooked). It may not be legally imported into the U.S.
FOIE GRAS SEMI-CONSERVÉ: Cooked and pasteurized but not sterilized; it will last for several months if refrigerated.
FOIE GRAS EN CONSERVE: Foie gras which has had the bejabbers and much of the taste and texture boiled out of it. Sterilized, then canned or put up in glass jars.