Attributive and as postpositive (also in à la Périgueux). Designating a sauce made from truffles cooked with fortified wine, or a dish made with this sauce.
Origin
Early 19th century; earliest use found in Lord Byron (1788–1824), poet. From Périgueux, the name of a city in the Périgord region in the département of Dordogne in south-west France, which produces truffles. Compare French à la Périgueux.