How to Make Croque Monsieur and Croque Madame

Gruyère is the classic cheese (US standards require it to be at least 90 days old, per 21 CFR 133.149), nutty and savory, and it goes both inside the sandwich and on top.

The name comes from the French croquer, to crunch. Add a fried egg and you have a croque madame. Everything below is a straightforward bake: make a small béchamel, build the sandwiches, and broil until the top blisters.

Croque monsieur at a glance

This croque monsieur table gives the key numbers.

How to make croque monsieur

Here is how to make croque monsieur at home with a simple béchamel.

Ingredients for croque monsieur

These are the ingredients for croque monsieur, split between the béchamel and the sandwich.

• Béchamel: 1 tablespoon (14 g) butter
• Béchamel: 1 tablespoon (8 g) all-purpose flour
• Béchamel: 3/4 cup (180 ml) whole milk, warmed
• Béchamel: pinch of salt, white pepper and freshly grated nutmeg
• Sandwich: 4 slices pain de mie or sturdy white sandwich bread
• Sandwich: 1 tablespoon (14 g) soft butter, for the bread
• Sandwich: 1 teaspoon Dijon mustard
• Sandwich: 4 slices good cooked ham (about 4 oz or 115 g)
• Sandwich: 5 oz (140 g) Gruyère, coarsely grated, divided
• Madame: 2 eggs, optional, for croque madame

Steps for making croque monsieur

Follow these steps for making croque monsieur, starting with the béchamel.

1. Heat the oven to 425°F (220°C) with a rack in the upper third and line a sheet pan with parchment.
2. Melt the butter in a small saucepan over medium heat, whisk in the flour, and cook 1 minute without browning.
3. Whisk in the warm milk a splash at a time, then simmer 3 to 4 minutes, stirring, until it coats a spoon like heavy cream. Season with salt, white pepper and nutmeg, and stir in 1 oz (30 g) of the Gruyère.
4. Butter one side of each bread slice and toast them butter side down in a skillet over medium heat for 1 to 2 minutes until pale gold.
5. Lay two slices toasted side down on the pan, spread with mustard, and top each with 2 slices ham and 1 1/2 oz (40 g) Gruyère.
6. Close with the other slices, toasted side in, and spread the béchamel over the tops, right to the edges.
7. Scatter the remaining Gruyère over the béchamel and bake 8 to 10 minutes until bubbling at the edges.
8. Switch to broil for 1 to 2 minutes, watching closely, until the top is blistered and golden brown in spots.
9. For croque madame, fry the eggs in butter until the whites are set, then slide one onto each sandwich, and serve at once.

The best cheese for croque monsieur

The best cheese for croque monsieur is Gruyère, which melts smoothly and tastes nutty and savory without turning oily. Read the Gruyère profile for how age changes it.

Emmental or Comté can substitute or be blended in; see Swiss vs. Gruyère vs. Emmental for the differences. Use cheese you grate yourself: pre-shredded bags are coated with anti-caking starch that keeps the top from fusing smoothly. A little cheese melted into the béchamel makes a Mornay sauce, and the technique behind a sauce that does not split is in the cheese sauce guide.

Croque monsieur mistakes and fixes

Croque monsieur mistakes mostly come from the béchamel and the broiler.

• Lumpy béchamel. The milk was cold or added too fast. Warm it and add it gradually while whisking.
• Thin, runny sauce. It needed another minute of simmering. It should coat a spoon.
• Greasy top. The cheese broke from too much heat. Keep the broil short and use Gruyère rather than a very old, dry cheese.
• Soggy sandwich. Skip the toasting step or add too much sauce inside. Toast the bread and keep the sauce on top.
• Burnt top, cool middle. Bake first, then broil briefly; do not start under the broiler.

Croque madame and other croque monsieur variations

Croque madame is the best-known of the croque monsieur variations, and it simply adds a fried egg on top. Egg yolks that stay runny are not cooked to the 160°F that USDA lists for egg dishes (FSIS temperature chart), so people who are pregnant, elderly or immunocompromised should cook the yolk through or use pasteurized eggs.

• Croque provençal: add sliced tomato under the cheese.
• Croque forestier: layer in sautéed mushrooms.
• Smoked version: swap in smoked ham or a little smoked cheese.

Storing croque monsieur

Storing croque monsieur works best in parts, since the sandwich is best straight from the broiler. Make the béchamel up to 2 days ahead and press plastic wrap on its surface; reheat it gently with a splash of milk. Refrigerate leftover sandwiches within 2 hours and eat them within 3 to 4 days, reheated to 165°F (FSIS leftovers guidance). Reheat in a 350°F (175°C) oven for 10 to 12 minutes; the microwave softens the crust.

Croque monsieur questions

Here are short answers to common croque monsieur questions.

What is the difference between a croque monsieur and a grilled cheese?

A croque monsieur adds ham and a béchamel top that is baked or broiled, while a plain grilled cheese is just buttered bread and cheese cooked in a pan.

What is a croque madame?

A croque madame is a croque monsieur topped with a fried egg.

What cheese goes on a croque monsieur?

The usual cheese for croque monsieur is Gruyère, both inside and on top. Emmental and Comté also work.

Can you make croque monsieur ahead of time?

Croque monsieur can be partly made ahead: the béchamel keeps 2 days, and you can assemble the sandwiches an hour before baking.

Can you make croque monsieur without béchamel?

You can skip the béchamel, but then it is a ham and cheese melt, not a croque monsieur. A thin, quick sauce is worth the five minutes.

Make your first croque monsieur

A croque monsieur needs a smooth béchamel, real Gruyère and a short broil. Make one pair, then add the egg for madame.