What part of a goose is used to make foie gras?

Foie gras is a luxury food item made from the liver of a duck or a goose severely fattened by force-feeding. This dish, regarded as a delicacy by some, has been the source of much controversy. Many people consider its production process to be exceedingly cruel and inhumane.

"Foie gras" is French for fatty liver. By French law, foie gras must be made from the liver of a duck or goose fattened by the process of gavage. Gavage involves force-feeding the animal corn through a feeding tube until its liver has grown to unnaturally large proportions. This process has drawn much criticism.