Croque Madame Sauce (quick & easy recipe!) - Heavenly Home Cooking (2024)

Have you ever had a croque monsieur, that delightful sandwich made with ham and Gruyère cheese and filled and topped with a creamy béchamel? If so, you know how tasty it is! We shared the croque madame, a version of the croque monsieur that is perfect for breakfast. One of the things that makes these sandwiches so unique is the sauce that goes inside and on top. As such, I wanted to share this wonderful croque madame sauce with you because it deserves its own post!

Traditionally, both sandwiches take a béchamel (or white sauce), which is made with butter, flour and milk. However, this sauce has added cheese making it a mornay (or cheese sauce). Mornay is basically béchamel with added cheese, typically Gruyère, but we are going with the less expensive and more readily available Swiss cheese. If this sounds intriguing to you, read on to learn how easy it is to make and how delicious it tastes!

🥄 Equipment

First things first, you will need a small saucepan and a whisk (affiliate links) to make this delicious breakfast sandwich sauce.

🥛 Ingredients

• Unsalted butter (2 tablespoons). Adds flavor and helps to thicken the sauce. You can also use salted butter. If you do, you won't need to add as much salt later.
• All-purpose flour (2 tablespoons). This is used to thicken the sauce.
• Warmed milk (1 cup). Be sure to warm the milk first. Warmed milk will prevent the butter from cooling down and solidifying. Making sure the milk is warm first will keep the sauce nice and smooth.
• Shredded Swiss cheese (¾ cup). You can also use Gruyère cheese, but it is more expensive than Swiss and not as readily available. Classic mornay sauce is traditionally made with Gruyère cheese (source). If you decide to try it, you can usually find it in the gourmet section of your grocery store.
• Dijon mustard (1 teaspoon). Adds flavor and blends very well with the ham and cheese.
• Salt & pepper to taste. You can add as much or as little as you like. Use freshly grated pepper for the best flavor.

📝 Instructions

Reduce heat to medium-low and simmer, whisking frequently, until thickened, about 5 minutes.

🗬 Tips

This recipe is really simple to make so there isn't much that can go wrong. However, my best tip is to keep that whisk moving when the sauce is on the stovetop. Burned croque madame sauce doesn't taste very good!

The sauce will solidify and become quite thick once it cools. This is fine. If you want a pourable sauce, you can heat it in the microwave to loosen it up. Heat on high for 30 seconds at a time, stirring in between, until it is the consistency that you would like.

❄️ Storage and Reheating

Be sure to refrigerate any leftover sauce in an airtight container within two hours of making it. It will keep in the fridge for up to 4 days.

You can also freeze it. It is best stored in a lidded mason jar. Make sure the sauce is completely cool, then fill the jar, leaving 1 inch at the top to allow for expansion. It will keep in the freezer for up to 6 months. (source).

To reheat, remove the lid and heat in the microwave or on the stovetop. Stir frequently while reheating to prevent curdling.

❔ FAQs

These breakfast sandwiches have some pretty great sauces of their own. Check them out!

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Recipe

📚 References and Further Reading

1. Recipe from The Breakfast Bible (affiliate link) by Kate McMillan for Williams Sonoma.
2. "How long can you keep homemade cheese sauce?" by Still Tasty.
3. "What causes cheese sauce to have a gritty texture?" by Sara Moulton.