Foie gras (French for 'fat liver') is made of the liver of geese or ducks, and is considered a delicacy in the French cuisine.
Normally, foie gras is produced by force-feeding the animals, with up to 25% of their body weight per day, so that the liver grows very fast. The force-feeding is done through funnels and tubes, under pressure.

Production in the Netherlands is illegal, because of animal cruelty, but the sale is not. This is why animal rights organizations fight against the sale of foie gras.

Foie gras, if produced without force-feeding, can still be on the menus.