Croque Monsieur

Ingredients

• 1 1/2 tspsalted butter
• 1 1/2 tspunbleached plain flour
• 60 ml (1/4 cup)milk
• 1/2 tspsalt
• Pinchground white pepper
• Pinchnutmeg
• 2–3 tbsp (30–45 ml)Gruyère, Emmental or Swiss cheese, grated
• 4 thick slicesFrench or sourdough bread
• To tasteDijon mustard
• 2 slicescooked ham
• 113 g (4 oz)Gruyère, Emmental or Swiss cheese, sliced

Instructions

1. 1

   Preheat the grill

   Set the oven grill to medium-high.

2. 2

   Make the béchamel

   Melt the butter in a small saucepan. Whisk in the flour and cook for 1 minute over medium-low heat. Gradually pour in the milk, whisking so the flour mixture blends evenly. Turn the heat up to medium and stir constantly for 2–3 minutes, until thickened. Season with the salt, white pepper and nutmeg, then whisk in the grated cheese until melted and smooth. Take the sauce off the heat.

3. 3

   Toast the bread

   Arrange all 4 slices of bread on a baking sheet and grill for 2–3 minutes, until toasted. Take them out of the oven.

4. 4

   Build the sandwiches

   Spread Dijon mustard over the softer side of 2 slices of toast. Top each with a slice of ham and sliced cheese. Return these 2 topped slices to the oven and grill for 1–2 minutes, until the cheese has melted.

5. 5

   Add the sauce

   Place a remaining slice of toasted bread on each sandwich and cover each with béchamel. Return them to the oven and grill for 3–4 minutes, until the sauce is bubbling and golden.

6. 6

   Serve warm

   Serve the sandwiches while warm.

What is a croque monsieur?

The croque monsieur is a French hot sandwich made with ham and cheese, toasted and served with a rich topping. Its name is associated with a crisp, hot bite, and it is a familiar feature of French café cooking.

This version builds flavour in layers: Dijon mustard cuts through the savoury ham and cheese, while a cheese-enriched béchamel turns the top golden under the grill.

Nutrition and macros by portion

The nutrition label shows one serving as written: 520 calories, 31g protein, 44g carbs, 24g fat.

The bread supplies most of the carbohydrates, while the butter, cheese and béchamel contribute much of the fat; ham and cheese provide most of the protein. Pair a sandwich with a simple salad or other vegetables for a more balanced plate.

The béchamel makes the difference

Roux first: cooking the flour briefly in melted butter helps it blend into the milk without a raw flour taste. Add the milk gradually while whisking to keep the sauce smooth.

Cheese last: stir in the grated cheese once the sauce has thickened, then take the pan off the heat when it melts. The sliced cheese goes inside the sandwich, while the grated cheese enriches the sauce.

Toast before assembling

The initial grill gives the bread a head start before it is covered with toppings and sauce. Keep an eye on it, since thick slices can toast quickly under a hot grill.

The recipe uses the softer side of the toast for mustard. That puts the flavour against the ham and cheese while the outside remains ready to crisp further.

Watch the grill closely

Melted cheese: the topped slices need only 1–2 minutes under the grill. Take them out once the cheese has melted rather than waiting for browning.

Golden sauce: after adding the béchamel, grill for 3–4 minutes, looking for bubbles and a golden surface. Grill strength can vary, so use those visual cues alongside the timing.

Choosing bread and cheese

Bread: thick French bread or sourdough gives the sandwich a sturdy base for the ham, cheese and sauce. Slices of similar thickness help them toast at the same rate.

Cheese: Gruyère is the recipe's first choice, with Emmental or Swiss cheese offered as alternatives. Use the grated cheese in the sauce and the sliced cheese in the filling.

Serve it simply

Serve the croque monsieur straight from the oven, while the centre is hot and the sauce is still bubbling. A crisp green salad or lightly dressed leaves make a fresh contrast to the rich sandwich.

If serving two, plate the sandwiches promptly after the final grill so the bread stays crisp beneath the sauce.

Recipe notes & tips

• Grate the sauce cheese finely so it melts smoothly into the béchamel.
• Whisk continuously as you add the milk to help prevent lumps.
• Keep the bread in a single layer on the baking sheet so it toasts evenly.
• Use the grill's visual cues as well as the timings, since grills vary in strength.
• Have the mustard and fillings ready before the toasted bread comes out of the oven.

Variations

• Use Emmental: swap it for Gruyère in both the sauce and filling.
• Try sourdough: its tangy flavour pairs well with the ham and cheese.
• Adjust the mustard: spread on a little more or less to suit your taste.
• Add a salad: serve with dressed leaves for a fresh side.
• Choose French bread: use thick slices for a traditional-style base.

Common mistakes to avoid

• Lumpy sauce: whisk the milk in gradually and keep stirring as it thickens.
• Over-toasting the bread: check it after 2 minutes, as grill strength varies.
• Uneven melting: arrange the sliced cheese across the bread rather than in a thick pile.
• Burnt topping: watch closely during the final 3–4 minutes under the grill.
• Serving too late: bring the sandwiches to the table while the sauce is still hot and bubbling.

How to store

Store leftovers covered in the fridge and eat within 2 days. Reheat in an oven or under the grill until hot throughout; the bread will be less crisp than when freshly made.

Frequently asked questions