The Italian Quattro Colli Pecorino Romano grated cheese is a tasty and aromatic, slightly spicy and salty cheese made from sheep's milk. It is used in many traditional Italian pasta dishes, such as Amatriciana and Carbonara, and in Roman Cacio e pepe pasta it is the key ingredient. Pecorino Romano has been produced since the time of the Roman Empire. PDO — Protected designation of origin.