Croque Monsieur — France’s Most Gloriously Decadent Sandwich
Three cheeses. Béchamel sauce. Smoky ham. Dijon mustard. Butter-seared and oven-finished until golden and gloriously molten. This is the sandwich the French perfected — and once you taste it, every other grilled cheese will feel like a compromise.
INGREDIENTS
- 2 tablespoons unsalted butter
- 2 tablespoons all-purpose flour
- 0.5 cups whole milk
- 0.3 cups heavy cream
- 0.3 teaspoons nutmeg
- 0.3 teaspoons black pepper
- 4 thick slices white sandwich bread
- 150 grams smoked ham, thinly sliced
- 80 grams Gruyère cheese, grated
- 4 slices Swiss cheese
- 30 grams Parmesan, finely grated
- 2 tablespoons Dijon mustard
- 1 tablespoons unsalted butter (for pan-frying)
STEPS
- Start the béchamel roux: Heat 0.5 cups whole milk and 0.3 cups heavy cream together in a small saucepan over medium heat just until steaming — do not boil. Remove from heat and set aside. In a separate medium saucepan, melt 2 tablespoons unsalted butter over low heat. Add 2 tablespoons all-purpose flour and stir constantly for 3 minutes to cook out the raw flour taste — the mixture should stay pale and white, not golden.
- Finish the béchamel: Pour half the warm milk mixture into the roux, whisking constantly until fully incorporated and smooth. Add the remaining milk mixture and whisk again until combined. Stir in 0.3 teaspoons nutmeg and 0.3 teaspoons black pepper. Continue cooking over medium heat, stirring constantly, until the béchamel is thick enough to spread like peanut butter — about 2 minutes. Remove from heat and set aside.
- Assemble the sandwiches: Preheat your oven to 200°C (390°F). Spread a generous layer of béchamel over one side of each slice of 4 thick slices white sandwich bread. On two of the slices, lay 2 slices of 4 slices Swiss cheese on top of the béchamel, then spread 2 tablespoons Dijon mustard directly over the cheese. Layer on 150 grams smoked ham, thinly sliced, spread with a little more mustard, then top with another layer of 4 slices Swiss cheese. Close each sandwich with the remaining béchamel-spread bread slices.
- Pan-sear until golden: Melt 1 tablespoons unsalted butter (for pan-frying) in an oven-safe skillet over medium heat. Once foaming, add the sandwiches and cook for 2–3 minutes per side until deeply golden and crisp. Press down gently with a spatula as they cook.
- Top with cheese & béchamel: Transfer the seared sandwiches to a baking tray. Spread the remaining béchamel generously over the top of each sandwich. Scatter over 80 grams Gruyère cheese, grated, then finish with 30 grams Parmesan, finely grated for a salty, savory crust.
- Bake & grill: Bake for 15 minutes until the cheese is fully melted and bubbling. Switch to the grill or broiler setting and cook for a further 3 minutes until the top is deeply bronzed and gloriously golden. Watch closely — it can go from perfect to burnt quickly.
- Serve immediately: Transfer to plates immediately and serve while hot and oozing. Pair with a crisp green salad, thin fries, or simply eat it as it is — straight from the pan, standing at the kitchen counter, with no regrets whatsoever.
NOTES
Key tips for perfection:
- Warm your milk and cream before adding to the roux — this is the trick to a completely lump-free béchamel.
- The béchamel should be thick enough to spread like peanut butter. If it’s pourable, keep cooking and stirring.
- Always spread Dijon mustard onto the cheese layers, not the bread — this way the flavor stays distinct and doesn’t disappear into the sauce.
- Don’t rush the pan-sear step. A deep golden crust on both sides of the sandwich is what gives it structure before it goes into the oven.
- Eat immediately. This sandwich waits for no one.
Make it a Croque Madame: Top the finished sandwich with a sunny-side-up fried egg. It sounds excessive. It is excessive. Do it anyway.
Serving ideas: Classic bistro-style with a crisp green salad and thin fries · With a bowl of French onion soup · As a brunch centerpiece with fresh fruit on the side.