pie and mash, traditional British comfort food that was once a staple of London’s working class in the city’s East End. It consists of a minced-beef filling (historically, leftover scraps of meat and vegetables) baked in a pastry crust and served with mashed potatoes and a thin green parsley sauce called liquor (which actually contains no alcohol). Since the 19th century, a common side dish has been jellied eels, and the liquor sauce was traditionally made with the liquid left over from stewing or boiling the eels. Contemporary pies come in a wide variety—such as chicken, fruit, and vegetarian—and pie-and-mash shops remain popular throughout London, especially in the East End.