Tarts

There was an Old Person of Pett Who was partly consumed by regret; He sat in a cart And ate cold Apple Tart Which relieved that Old Person of Pett

EDWARD LEAR,

NONSENSE OMNIBUS, 1943; ca. 1846

When is a pie a tart? Both pies and tarts are known as les tartes in French. But today, the general understanding is that a tart is open-face, with a single bottom crust, and usually (though not always) baked in a shallow pan with straight sides.