Pecorino Romano is a hard, salty, Italian cheese made, as the name implies, in or near Rome. This cheese is made from sheep's milk. Like parmesan, pecorino is used mainly in cooking. Substituted in any recipe calling for parmesan, pecorino gives the end result a sharper flavor. Pecorino cheeses are generally aged up to a year. As they age they develop a brittle, hard texture, and the rind yellows. The younger the cheese, the softer and whiter it is.