Yes, cheese is the only thing that differentiates Mornay sauce from Béchamel sauce. And that’s probably the reason why it isn’t counted as one of the five mother sauces in French cooking. Mornay sauce is simply a variant of Béchamel sauce.
So, if you want to know more about Béchamel sauce, there are two posts about it. One is a recipe. The other is a background on its origin. Béchamel sauce may be named after a Frenchman but the sauce itself has been in use long before the French claimed it as their own. It’s all there in the linked post above.
Now, how to make Mornay sauce. You start by making Béchamel sauce.
And the first step is cooking a mixture of melted butter and all-purpose flour. You’re cooking the flour here, actually, so that when the sauce is done, it won’t leave a powdery sensation in the mouth.
The next step is adding the milk. Little by little, stirring as you pour, whisking after each addition to make sure no lumps form. When all the milk has been incorporated, you have your Béchamel sauce. Now, we transform that into Mornay sauce.
While the Béchamel sauce is hot but with the heat off, add shredded Gruyère cheese or your cheese of choice, stir until the cheese melts, then season the sauce.
And just how is Mornay sauce used? Well, there are lots of ways to incorporate it into a dish, but our favorite is adding it to baked mac and cheese.
Mornay sauce (French cheesy white sauce)
- In a saucepan, melt the butter.
- Add the flour, all at once.
- Stir the butter and flour mixture until smooth.
- Cook over medium heat, stirring occasionally, for five minutes to make a blonde roux.
- Pour the milk in a thin stream, mixing as you pour.
- Keep pouring the milk, and stirring, until all the milk has been fully incorpotated.
- Off the heat, stir in the shredded Gruyère until melted.
- Season the Mornay sauce with nutmeg, salt and pepper.