Croque Monsieur (French Ham and Cheese Sandwich)
Why this recipe works
- Layered savoury flavour: Dijon mustard, cured ham and Gruyère add sharpness, saltiness and nuttiness without needing a long ingredient list.
- Creamy centre: The béchamel keeps the sandwich rich and soft beneath the cheese topping.
- Golden, bubbling top: Baking on a hot tray helps the bread heat quickly while the cheese and sauce brown into a crisp, gratin-like finish.
Get the most out of this recipe
Ingredient notes
- Choose a good melting cheese: Gruyère gives the classic nutty flavour, while Emmental makes a slightly milder sandwich with a more elastic melt.
- Use mustard for balance: Dijon cuts through the richness of the béchamel and cheese; whole-grain mustard gives a gentler heat and more texture.
- Spread the sauce to the edges: Covering the bread fully with béchamel helps protect the top from drying out and encourages even browning.
Texture tips
- For a smoother béchamel: Whisk the milk in gradually and keep the heat at medium so the sauce thickens evenly without catching.
- For a deeper golden top: Use the preheated baking tray as directed and bake until the topping is fully bubbling and browned.
- Avoid a soft base: Reheat leftovers in the oven rather than the microwave, which can make the bread lose its structure.
Common mistakes
- Making the sauce too thin: Cook the béchamel until it coats the back of a spoon; if it is runny, it can slide off the sandwich.
- Letting the roux catch: Cook the butter and flour briefly to remove the raw flour taste, but keep whisking so it does not brown or burn.
- Stopping before it bubbles: The sandwich should be piping hot with the topping fully bubbling, especially when serving to more vulnerable diners.
Make-ahead tips
- Prepare components ahead: The cheese can be grated and the béchamel made in advance, then the sandwiches assembled just before baking.
- Reheat in the oven: Warm leftovers on a baking tray at 200°C (390°F) until piping hot and bubbling again.
- Best freshly baked: Croque monsieur is at its best straight from the oven, when the top is crisp and the centre is still creamy.
Equipment you'll need
Ingredients
Instructions
- Heat the oven to 220°C (430°F) and set a baking tray inside to warm. Grate the Gruyère and keep it to one side.
- Make the béchamel: melt the butter in a saucepan over medium heat until foaming, then whisk in the flour and cook for 1 minute. Gradually whisk in the milk until smooth, then cook for 3 to 5 minutes, whisking, until thick enough to coat the back of a spoon. Season with nutmeg and black pepper, then take off the heat.
- Lay out the bread and spread the Dijon mustard over 2 slices. Top each with half the ham and a good handful of the Gruyère, then close with the remaining bread.
- Carefully remove the hot tray from the oven and set the sandwiches on it. Spoon the béchamel over the tops, spreading it right to the edges, then sprinkle over the remaining Gruyère. Bake for 8 to 10 minutes until bubbling and deeply golden on top.
Recipe notes
Serving suggestions
This recipe pairs well with:
Tips
- For a smoother sauce, add the milk in a steady stream while whisking, and keep the heat at medium so it thickens without catching.
- If you are sensitive to raw flour taste, make sure the butter and flour cook for a full minute before adding the milk.
- This dish contains dairy; if serving to pregnant people, young children, older adults, or anyone immunocompromised, ensure the sauce is piping hot and the topping is fully bubbling before serving.
Substitutions
- Replace Dijon mustard with whole-grain mustard for a milder heat and a coarser texture.
- Replace Gruyère cheese with Emmental cheese for a slightly milder, more elastic melt.
Storage
- Refrigerate up to 2 days
- Cool, then refrigerate in a sealed container for up to 2 days. Reheat on a baking tray at 200°C (390°F) for 8 to 12 minutes until piping hot and the top is bubbling again; avoid microwaving if you want to keep the bread from going soft.
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Recipe overview
- Servings: 2 servings
- Total time: 25min (20min active)
- Difficulty: Easy
- Cuisine: French
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Allergens:
Gluten Milk Wheat
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