Foie gras is a French term (it means 'fatty liver') which exclusively defines the liver of geese and ducks, used for pâté; for this purpose, the birds are fattened beyond measure with a particular farming system that forces them to an almost total immobility. As a result their liver swells, reaching a weight up to 1 kg in geese and 400 g in ducks.

Foie gras is marketed, usually around Christmas time, either canned, raw or whole. However, it can also be found already as a pâté, usually packaged in porcelain terrines.