Croque Monsieur Recipe

Ingredients

• 360 ml (1½ cups)milk
• 57 g (4 tablespoons)unsalted butter
• 31 g (¼ cup)plain flour
• ¼ teaspoonsalt
• ⅛ teaspoon eachground nutmeg and white pepper
• A pinchcayenne pepper (optional)
• 8 slices, about 1.3 cm (½ inch) thickcountry-style sourdough bread or pain de mie
• 170 g (6 oz)Gruyère, thinly sliced
• 170 g (6 oz)ham slices, preferably Black Forest
• 30 ml (2 tablespoons)Dijon mustard
• 57 g (4 tablespoons), dividedunsalted butter
• 30 ml (2 tablespoons), dividedolive oil
• 85 g (3 oz; ¾ cup)Gruyère, shredded
• 25 g (¼ cup)Parmesan, finely grated

Instructions

1. 1

   Prepare the oven

   Heat the oven to 200°C (400°F). Line a large baking sheet, about 53 × 38 cm (21 × 15 inches), with parchment paper.

2. 2

   Cook the roux

   Melt 57 g (4 tablespoons) of unsalted butter in a medium or large saucepan over medium heat. Turn the heat to low, add the flour and whisk continuously for 2 minutes.

3. 3

   Whisk in milk

   Take the pan off the heat. Whisk in about a quarter of the milk until smooth and thick, then add the rest a couple of tablespoons at a time, whisking smooth after each addition. Stir in the salt, nutmeg, white pepper and cayenne.

4. 4

   Thicken the sauce

   Bring the béchamel to a simmer, whisking for a few minutes until it is thick enough to spread, like butter or pudding rather than a runny sauce. Remove it from the heat.

5. 5

   Spread the béchamel

   Arrange all 8 slices of bread on the prepared baking sheet. Spread half the béchamel thickly over every slice, as you would butter toast.

6. 6

   Build the sandwiches

   On 4 slices of béchamel-covered bread, layer half the sliced Gruyère and all the ham, folding the ham to fit if needed. Spread a thick layer of Dijon over the ham, add the remaining sliced Gruyère, then close each sandwich with a remaining slice of bread, béchamel side down.

7. 7

   Brown the sandwiches

   Heat 15 ml (1 tablespoon) of the olive oil in a cast-iron skillet over medium heat. When hot, add some of the butter and let it melt. Working in batches, fry the sandwiches for about 2 minutes per side, pressing them occasionally with a spatula, until deeply golden. The cheese need not be fully melted yet. Return them to the lined baking sheet.

8. 8

   Add the topping

   Spread the remaining béchamel over the tops of the sandwiches. If it has become too cold or thick to spread, warm it gently and whisk in a splash of milk. Scatter over the shredded Gruyère and grated Parmesan.

9. 9

   Bake and grill

   Bake for 10–12 minutes, until the cheese has melted. Grill for a further 2–3 minutes, until the tops are golden.

10. 10

    Serve straight away

    Serve immediately with a fork and knife; the sandwiches are hot, gooey and messy to eat by hand.

What is a croque monsieur?

A croque monsieur is a French hot ham-and-cheese sandwich, traditionally made with bread, ham, cheese and often béchamel. Its name is commonly associated with the crisp, toasted bite of the sandwich.

This version layers Dijon mustard into the filling and adds béchamel and two cheeses on top. Sourdough gives the rich topping a sturdy, tangy base.

Nutrition and macros by portion

The nutrition label shows one serving as written: 900 calories, 43g protein, 55g carbs, 57g fat.

The bread supplies most of the carbohydrates, while butter, olive oil and the cheeses contribute much of the fat. Ham and Gruyère provide most of the protein, with the cheese and ham also contributing sodium. Pair a sandwich with salad or vegetables for a fresher, more balanced plate.

Why this béchamel works

Roux first: Cooking the flour briefly in butter helps form a smooth base for the sauce. Keep whisking over low heat so it cooks without browning.

Milk gradually: Add the milk in small amounts, whisking each addition smooth before adding more. This gradual approach helps prevent lumps.

Spreadable finish: The sauce needs to be thick enough to stay on the bread. If it firms up while you assemble the sandwiches, warm it gently and whisk in a splash of milk.

Choosing the bread and cheese

Bread: Thick slices of country-style sourdough or pain de mie support the filling and topping. Very thin slices can soften under the béchamel.

Gruyère: Sliced Gruyère melts inside the sandwich, while shredded Gruyère forms the top layer. Parmesan adds a savoury finish alongside it.

Ham: Black Forest ham is suggested for its smoky flavour, but the recipe works with other sliced ham as well.

Getting an even golden crust

Pan-frying browns the bread before the sandwiches go into the oven. Use medium heat and cook in batches so each sandwich has room to brown rather than steam.

Press lightly with a spatula as the sandwiches cook, turning after about 2 minutes per side. The cheese does not need to melt completely in the pan; baking finishes the job.

How to judge doneness

The sandwiches are ready to leave the oven when the topping cheese is melted after 10–12 minutes. A final 2–3 minutes under the grill adds a golden surface.

Keep an eye on them during grilling, since the topping can colour quickly. Serve as soon as they come out while the centre is still gooey.

Serving a croque monsieur

Serve these straight away with a fork and knife, as the béchamel-covered tops make them especially messy to pick up. A crisp green salad or simply dressed leaves bring freshness alongside the rich sandwich.

For a more substantial meal, serve with a light vegetable soup. Keep accompaniments simply seasoned so they do not compete with the ham, mustard and cheese.

Recipe notes & tips

• Measure the béchamel topping before assembling so you have enough for the sandwiches and their tops.
• Whisk continuously while cooking the roux to keep it smooth.
• Let the sandwiches brown in batches rather than crowding the skillet.
• Use a spatula to press the sandwiches gently for even contact with the pan.
• Watch closely during the final grilling because the cheese can brown quickly.
• Serve immediately for the best contrast between crisp bread and melted cheese.

Variations

• Use pain de mie: Swap in thick slices of pain de mie for a softer, more classic-style sandwich.
• Adjust the spice: Leave out the optional cayenne for a milder béchamel.
• Change the ham: Use another sliced ham if Black Forest ham is unavailable.
• Add greens: Serve with a dressed green salad to bring freshness to the plate.
• Try a croque madame: Top each finished sandwich with a fried egg just before serving.

Common mistakes to avoid

• Adding all the milk at once: Whisk it in gradually, smoothing the sauce between additions to avoid lumps.
• Using thin bread: Choose sturdy slices about 1.3 cm thick so they support the topping.
• Cooking over high heat: Keep the skillet at medium so the bread browns without scorching.
• Crowding the skillet: Fry in batches so the sandwiches brown evenly.
• Skipping the grill check: Watch the topping closely during the final 2–3 minutes to prevent over-browning.
• Serving too late: Bring the sandwiches to the table straight away while the cheese is still gooey.

How to store

For the best texture, serve the sandwiches immediately. Refrigerate leftovers in an airtight container for up to 3 days, then reheat in a 180°C oven until hot; the bread may be less crisp after storage.

Frequently asked questions