At its heart, the croque-madame is a fancy toasted ham and cheese sandwich. This French bistro staple features thinly sliced ham, shredded Gruyere cheese, decadent Mornay sauce and Dijon mustard.
But that’s not all: After the croque-madame sandwich is toasted, it’s slathered with even more sauce and topped with grated cheese, then broiled until golden brown and bubbly. As if that weren’t enough, the sandwich is topped with a fried egg as a final touch.
This hearty sandwich can be served at nearly any time of day, though in France it is most commonly served at lunch or dinner. It could even make for an extravagant breakfast or brunch recipe!
Croque-Madame vs. Croque-Monsieur
The croque-madame and croque-monsieur sandwiches are quite similar to each other (translated, croque means “bite,” while madame and monsieur mean “madam” and “mister,” respectively). However, unlike a croque-madame, the croque-monsieur does not have a fried egg on top. Some say the egg atop the sandwich resembles a woman’s hat, hence the “madame” name.
Ingredients for Croque-Madame Sandwiches
- Mornay sauce: This sauce is a variation on a classic French bechamel sauce. Bechamel is a white sauce made with flour, butter and milk. Mornay sauce includes the addition of cheese—typically Gruyere.
- Bread: Use a thick-sliced country white bread for this sandwich.
- Ham: Use thinly sliced deli ham. This is also a lovely leftover ham recipe for your holiday ham.
- Cheese: For the most authentic flavor, stick to Gruyere. This Swiss hard cheese has a nutty and creamy flavor. Comté, Emmenthaler, or even basic Swiss cheese can be used in a pinch.
- Mustard: Dijon mustard is another must for this recipe. This French mustard has a sharp and spicy flavor, and it perfectly complements the creaminess of the cheese and saltiness of the ham. You can even make Dijon mustard from scratch if you have the time.
- Egg: A fried egg is the pièce de résistance on this sandwich. It’s what transforms a croque-monsieur into a croque-madame. Our guide to how to fry an egg gives you tips and tricks for the perfect sunny-side up egg.
Directions
Step 1: Make the Mornay sauce
In a small saucepan, melt the butter over medium heat. Whisk in the flour, salt, pepper and nutmeg until smooth.
Gradually whisk in the milk. Bring the mixture to a boil.
Cook and stir until thickened, about one minute. Reduce the heat to low. Add the cheese, and stir until it’s melted. Keep warm.
Step 2: Prep the sandwich
On each of two bread slices, spread 2 tablespoons Mornay sauce, and top with 3 ounces ham and 1/4 cup cheese. If desired, spread Dijon mustard over the remaining two slices of bread. Place the bread, mustard side down, on top of the cheese. Spread the outsides of the sandwiches with 3 tablespoons butter.
Step 3: Toast the sandwiches
In a large cast-iron or broiler-safe skillet, toast the sandwiches over medium heat until they’re golden brown and the cheese is melted, two to three minutes on each side.
Spread the remaining Mornay sauce over top of the sandwiches. Sprinkle with the remaining 1/4 cup cheese. Preheat the broiler. Broil the sandwiches 4 to 6 inches from the heat until the tops of the sandwiches are bubbly and lightly browned, two to three minutes.
Step 4: Fry the eggs
Meanwhile, melt the remaining butter in a small nonstick skillet over medium-high heat. Break the eggs, one at a time, into the skillet. Reduce the heat to low. Cook until the whites are set and yolks begin to thicken, turning once if desired. Top each sandwich with a fried egg.
Croque-Madame Variations
- Add fresh herbs: For added fresh flavor, garnish each sandwich with freshly chopped herbs, such as chives, thyme or tarragon.
- Up the steaks: Pun intended! Replace the ham with leftover cooked steak, sliced thinly.
- Make it Monte Cristo-inspired: Add thinly sliced turkey to the mix to make this sandwich more like a Monte Cristo.
- Switch up the cheese: Instead of using Gruyere, experiment with other types of cheese such as sharp cheddar or mild mozzarella.
How to Store Croque-Madame Sandwiches
Ideally, you should eat the croque-madame sandwiches immediately. However, if you have leftovers, they can be stored in an airtight container in the refrigerator for three to five days.
Can you make croque-madame sandwiches ahead of time?
The Mornay sauce can be made up to five days in advance. Store it in the refrigerator, and reheat it on the stovetop over low heat. If you need to make the sandwiches ahead of time, follow all the steps through toasting the sandwiches. Then let them cool, and store them in an airtight container in the refrigerator.
To reheat, set the sandwiches on a baking sheet, and heat in a 350°F oven for 5 to 10 minutes, until heated through. Proceed with the recipe by preheating the broiler, spreading Mornay sauce on top and sprinkling with cheese. Fry the eggs, and top each sandwich just before serving.
Croque-Madame Tips
What can you serve with a croque-madame?
Stick with French bistro vibes by serving your croquet-madame with pommes frites (aka french fries), mixed greens with a lemon vinaigrette or gherkin pickles.
What can you do with leftover Mornay sauce?
Leftover Mornay sauce makes a tasting topping for baked chicken or vegetables like roasted asparagus, and it’s perfect as the white sauce in a lasagna recipe.
