Each cheese plays a special role in this French bread pizza: A combination of Parmesan and pecorino makes it especially nutty and salty; mozzarella melts evenly and a sharper deli-style provolone bridges the gap between them. Once you learn how to make the classic white sauce (technically a Mornay, which is a béchamel with cheese added), you’ll find dozens of ways to use it beyond pizza: Swap in an equal amount of grated Cheddar and toss it with pasta for an easy stovetop mac and cheese, or use Gruyère, slather the sauce over ham on toast, and broil until bubbly and browned. The sauce can be made up to 3 days ahead of time; store tightly covered in the refrigerator until ready to use.