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Learn to make a classic Mornay Sauce. This easy, creamy, cheesy white sauce can be served on its own, or added to other recipes.
What is Mornay Sauce?
Mornay Sauce is a béchamel sauce (roux-based white sauce) with shredded or grated cheese added to it.
Mornay Sauce is said to be named after the French Duke Phillippe de Mornay, and dates back to the 16th century. But others in the culinary world believe that the original version was made differently than it is today, in part because the flour and butter technique used to make béchamel sauce was not invented until a century later.
How to serve Mornay Sauce
There are many variations of Mornay Sauce – with different cheeses and ingredients added based on how you plan to serve it or use it in recipes. Some recipes add onions or shallots. Others add egg yolks to thicken the sauce even more.
- Some macaroni and cheese and white lasagna recipes include a Mornay Sauce – with cheddar and/or mozzarella added.
- It can be used in Mexican recipes – with Monterey Jack or Pepper Jack cheese added.
- Spoon it over seafood or vegetables – a stronger-flavored cheese such as Gruyère or Boursin are great options for this serving suggestion.
- Make our delicious Chicken Florentine!
Why you’ll love Mornay Sauce
- It’s luxuriously rich and very delicious!
- This sauce is so versatile and can be added to many different recipes.
- While it has a very fancy name, it’s actually very easy to make. Just be sure to have all of the ingredients already prepped and measured and close at hand before you start to cook. (Read Cook like a Pro with Mise en Place.)
Key Ingredients & Substitutions
- Butter – Unless otherwise stated in a recipe, we always cook with unsalted butter so we can season the dish to suit our tastes.
- All-purpose flour – This is used to create the roux, which thickens the sauce.
- Whole Milk – We do not recommend a lower fat milk for this sauce as the finished sauce will lose some of its richness.
- Cheese – We used Gruyere and Parmesan in our recipe today, but many other types of cheese can work, depending on how the sauce is used in a recipe or the foods the sauce is served with.
- Seasonings – Kosher salt, white pepper, nutmeg, and dry mustard are classic. You can vary the sauce flavor with other seasonings and spices.
- Onions (Optional) – Depending on how it’s served, onions or shallots can be sautéed in the butter first before adding the flour.
- Egg Yolks (Optional) – For a very rich Mornay, add two egg yolks towards the end of the cooking process. (Just be sure to temper the eggs by stirring a little of the sauce with the egg yolks to warm then, then whisk them in into the rest of the sauce. If you add the egg yolks in all at once, they will seize, and you’ll end up with chunks of egg in your sauce.)
Special Tools Needed
- Medium Saucepan – To heat the milk
- Large Saucepan or Medium Pot – To make the sauce
- Various Measuring Spoons and Cups
- Box Grater – To shred the Swiss Cheese and grate the Parmesan
- Ladle – Used to add the milk to the roux
How do I make Mornay Sauce?
- Heat milk in saucepan but do not boil.
- Melt butter in larger pan and once melted, add flour and cook three minutes.
- Ladle in the milk a little at a time, whisking after each addition.
- Add seasonings and both types of cheese and whisk to combine. Continue stirring to melt the cheese and blend the flavors.
- Assess sauce for thickness – add more milk to thin the sauce or add more cheese to thicken it.
Tips & Tricks
- The final thickness of the sauce can be easily changed. Add more cheese to make it thicker or add more milk to make it thinner. (Cold milk can be added at the end to get the sauce where you want it, no need to preheat.)
- When reheating, additional milk can be added to thin it down. Note that as the sauce cools, it will thicken up so plan to keep some extra milk on hand if you know ahead of time that you will reheat it.
- If you desire a thinner sauce from the start, cut back on the original amount of flour in the recipe by a few tablespoons. The rest of the recipe stays the same.
Frequently Asked Questions
- Is Mornay Sauce the same as Alfredo Sauce? No – Mornay starts with a roux (butter and flour) to create a thick sauce, while an Alfredo relies on heavy cream which is simmered to thicken.
- Can I make Mornay Sauce ahead of time? You can make the sauce in advance and reheat. Be prepared to add more milk, however, as it will thicken as it cools and will remain thicker once reheated.
- How do I store leftovers? Store refrigerated in a covered container for up to four days.
- How do I reheat leftovers? Reheat in a saucepan over medium low heat, stirring frequently but do not allow the sauce to boil. As mentioned above, be prepared to add more milk to thin the sauce since it thickens when cooled. Note that you could also microwave in short bursts on a lower power setting, stirring as you go. Just be sure not to heat too quickly.
- Can I freeze? No, this sauce will separate once thawed.
You might like these other Classic Sauce Recipes:
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6 tablespoons butter
7 tablespoons all-purpose flour
5 cups whole milk, plus more to adjust thickness to suit your needs
1 teaspoon kosher salt
1/2 teaspoon white pepper
1/4 teaspoon dry mustard
1/4 teaspoon freshly grated nutmeg
5 ounces Gruyère cheese shredded, plus more to adjust thickness to suit your needs
1/4 cup Parmesan cheese, grated
Optional – Chopped onions or shallots
Optional – 2 Egg Yolks, to make a very rich and decadent sauce
- Heat milk in a saucepan, but do not boil.
- In a medium pot over medium heat, melt butter and once melted, add flour and stir and cook for three minutes. (If you are using onions or shallots in your sauce, cook them in the butter first until translucent, then add flour and cook for the three minutes).
- Whisk in hot milk a ladle at a time, whisking vigorously after each addition. Sauce will be very thick to start and loosen with each ladle of hot milk whisked in. This process will eliminate lumps.
- Add salt, pepper, mustard, and nutmeg along with Gruyère and Parmesan cheese and whisk vigorously until the cheese is melted and the sauce smooth.
- Taste and check for thickness. Add more salt or pepper if needed and more milk or cheese as needed to your desired consistency and thickness. Depending on the type of cheese you use, the flavor and thickness will vary.
- For a rich and decadent sauce, place two egg yolks in a bowl and slowly whisk in a cup or two of the hot sauce to temper the eggs. Then pour this egg mixture back into the sauce and whisk.
- Serve with fish or chicken, use as a base for macaroni and cheese or lasagna, or serve over cooked vegetables.
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