Which cheeses are typically used in a Mornay sauce?

A Mornay sauce is a classic French béchamel sauce enriched with cheese, and it typically includes Gruyère and Parmesan as primary ingredients.

Gruyère is a hard cheese known for its creamy texture and slightly nutty flavor, which melts beautifully and adds richness to the sauce. Parmesan, being a hard, aged cheese with a savory and salty profile, contributes depth and enhances the overall flavor of the Mornay sauce. The combination of these two cheeses creates a smooth, well-balanced sauce that is commonly used in gratins, macaroni and cheese, and various pasta dishes.

The other cheese combinations listed do not align with the traditional recipe for Mornay sauce. For instance, mozzarella, while melty, does not provide the same depth of flavor as Gruyère or Parmesan. Feta introduces a tangy flavor that deviates from the creamy, rich profile of Mornay. Ricotta is light and creamy but lacks the melting characteristics seen in the cheeses typically used for this sauce, and gouda, although a good melting cheese, does not possess the sharp, savory flavor profile that works well in a Mornay.