You’re in the middle of making your CHEF iQ Quick Chicken Parm--and you realize you’re fresh out of Parmesan cheese! However, you do have pecorino. Can you swap it in? What’s the difference between these two hard grating kinds of cheese? And why do some recipes call for one over the other?

Parmigiano-Reggiano (the cheese’s true name, though it gets anglicized to Parmesan) is made from cow’s milk cheese in the northern Italian provinces of Parma and Reggio-Emilia. (In fact, true Parmigiano-Reggiano can only be made in this region.) The cheese is formed in giant wheels, etched with the distinctive dotted Parmigiano name on the sides, bathed in brine, and then aged for 12 to 36 months or more.

Pecorino Romano, on the other hand, is made from sheep’s milk. Pecora is the Italian word for sheep, and though it traditionally was made in the countryside near Rome, today it’s mostly produced in grassland-rich Sardinia. Though there are semi-soft pecorinos, the hard grating cheese is aged for about 8 months and, as with Parmigiano, it has its name etched in dotted letters on the rind.

Though both types of cheese are sublime for grating or shaving, they’re not so interchangeable. The sheep’s milk and shorter aging period give pecorino an assertive, sharp, herbaceous flavor, while Parmigiano’s character is mellower and nuttier. Reflecting their origins, Parmigiano tends to pair best with Northern Italian cuisine—think rich meat ragus, lasagnas, and classic pesto Genovese. Pecorino enhances Southern Italian dishes—such as cacio e pepe and bucatini all’Amatriciana, which are two popular examples that you can find on the CHEF iQ App. In a pinch, you can substitute pecorino for Parmigiano, but use about half as much, as pecorino is much saltier. Conversely, if you want to substitute Parmigiano for pecorino, use more and add a pinch of salt.

No matter which one you’re buying, search for a wedge that includes some rind. Check for the embossed name to ensure you’re getting the real deal!