Pecorino Romano is a popular, hard, salty-tasting cheese whose name is taken from the Italian city of Rome. It is mostly produced from the milk of sheep raised on the Italian island of Sardinia. Pecorino Romano is a DOC cheese, an acronym for Denominazione Di Origine Controllata, meaning the cheese is carefully regulated under Italian law and must meet specific production standards, according to author Laura Martinez in her book, "The Everything Cheese Book." There are several cheeses that you can use as a substitution for Pecorino Romano, although they will all have a slightly different taste.
Certain types of Asiago cheese are made in the United States, but official DOC Asiago cheese is made in the Italian Alps town of Asiago. Asiago has a crumbly, salty texture similar to Parmesan or Pecorino Romano and is often used as a substitute for these cheeses in many recipes. Unlike Pecorino Romano cheese, Asiago cheese is made from cow's milk so it has a slightly different flavour.
Parmigiano-Reggiano is another hard Italian cheese that is referred to as Parmesan cheese when it is not made in Italy. It is a popular substitute for Pecorino Romano cheese in many Italian recipes. True Parmigiano-Reggiano cheese is made in Northern Italy in Parma, Reggio Emilia, Modena and surrounding Italian provinces, according to the Parmigiano-Reggiano Cheese Consortium. It is a hard, crumbly cheese made from cow's milk and is DOC protected. You can find Parmesan cheese, which is a cheaper substitute for Parmigiano-Reggiano, in most cheese and grocery stores.
Gouda cheese is named after the Dutch city Gouda, however, it is made throughout the entire world. The best aged Gouda comes from the Netherlands. There are several varieties of aged Gouda cheese, referred to in Dutch as "Oud", meaning old, or "Extra oud", meaning extra old. The older the cheese, the harder and more crumbly it is, making the oldest cheeses an excellent substitute for Pecorino Romano cheese in many types of recipes. The texture resembles that of many aged Italian cheeses. Aged Gouda cheeses have a nutty, granular texture.
According to author Laura Martinez, Grana Padano is often mistaken for Parmigiano-Reggiano cheese. It is another DOC cheese whose name literally comes from the fact that it is a cheese with a grainy, or "grana", texture. The cheese is often considered to be inferior to Parmigiano-Reggiano cheese but is often chosen by many Italians for its cheaper price. Grana Padano can be used as a substitute for Pecorino Romano cheese due to its similar crumbly, dry texture and nutty, salty flavour.