Ravioli (plural form; singular: raviolo) are a type of dumpling composed of a filling sealed between two layers of thin pasta dough. Usually served either in broth or with a pasta sauce, they originated as a traditional food in Italian cuisine. Ravioli are typically square, though other forms are also used, including circular or semi-circular (mezzelune). Other related filled pastas include the ring-shaped tortellini and the larger tortelloni.