📝 About This Recipe
Originating in French cafés in the early 1910s, the Croque Monsieur is the sophisticated, golden-brown pinnacle of the grilled cheese world. This recipe elevates the classic with a velvety, nutmeg-infused Mornay sauce, salty Gruyère cheese, and high-quality jambon de Paris tucked between buttery slices of brioche. It is a decadent, crunchy-yet-creamy masterpiece that brings the spirit of a bustling Saint-Germain bistro right to your kitchen.
🥗 Ingredients
The Mornay Sauce
- 2 tablespoons Unsalted butter (high quality, European style preferred)
- 2 tablespoons All-purpose flour
- 1 cup Whole milk (warmed slightly to prevent lumps)
- 1/4 cup Gruyère cheese (finely grated)
- 1 teaspoon Dijon mustard (for a subtle tang)
- 1/8 teaspoon Nutmeg (freshly grated is best)
- 1 pinch Kosher salt and black pepper (to taste)
The Sandwich Assembly
- 4 slices Brioche or Pain de Mie (cut 3/4 inch thick)
- 2 tablespoons Unsalted butter (softened for spreading)
- 2 teaspoons Dijon mustard (for spreading on the bread)
- 4 slices Jambon de Paris (or high-quality unsmoked deli ham)
- 1.5 cups Gruyère cheese (shredded, divided for filling and topping)
- 2 tablespoons Parmigiano-Reggiano (finely grated for a salty crust)
👨🍳 Instructions
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1
Preheat your oven to 400°F (200°C) and line a small baking sheet with parchment paper or a silicone mat.
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2
Begin the Mornay sauce: In a small saucepan over medium heat, melt 2 tablespoons of butter until foaming.
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3
Whisk in the flour and cook for 1-2 minutes, stirring constantly. Do not let the flour brown; you want a 'blond' roux.
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4
Slowly pour in the warmed milk while whisking vigorously to ensure there are no lumps. Continue to cook, whisking often, until the sauce thickens enough to coat the back of a spoon (about 4-5 minutes).
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5
Remove the sauce from heat. Stir in 1/4 cup of grated Gruyère, the nutmeg, and 1 teaspoon of Dijon mustard. Season with salt and pepper to taste. Cover and set aside.
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6
Lightly butter both sides of all four bread slices. Place them on the baking sheet and toast in the oven for 3 minutes per side until very lightly golden.
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7
Remove the bread from the oven. Spread a thin layer of Dijon mustard on two of the slices, followed by a generous tablespoon of the Mornay sauce.
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8
Layer two slices of ham onto each prepared bread slice, folding the ham so it fits perfectly within the edges of the bread.
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9
Sprinkle about 1/4 cup of shredded Gruyère over the ham on each sandwich, then top with the remaining two slices of bread.
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10
Spoon the remaining Mornay sauce generously over the top of each sandwich, spreading it all the way to the edges to prevent the crusts from burning.
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11
Sprinkle the remaining Gruyère and the Parmigiano-Reggiano over the sauce-covered tops.
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12
Bake for 10-12 minutes until the cheese is melted and bubbling. For a perfect finish, turn on the broiler for the last 1-2 minutes until the top is speckled with golden-brown spots.
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13
Allow the sandwiches to rest for 2 minutes before serving to let the sauce set slightly. Serve warm with a knife and fork.
💡 Chef's Tips
Use a sturdy bread like Brioche or Sourdough; thin white sandwich bread will go soggy under the weight of the sauce. Always grate your own cheese from a block; pre-shredded cheese is coated in potato starch and won't melt as smoothly into the sauce. Spread the Mornay sauce all the way to the very edge of the bread to act as an insulator, keeping the crusts tender-crisp rather than hard. Don't skip the nutmeg; it is the secret ingredient that gives French white sauces their characteristic 'je ne sais quoi' depth. If you want to turn this into a 'Croque Madame,' simply top the finished sandwich with a sunny-side-up fried egg.
🍽️ Serving Suggestions
A simple green salad with a sharp vinaigrette to cut through the richness of the cheese. Cornichons (French tart pickles) served on the side for a crunchy, acidic contrast. A crisp, dry white wine like a Sancerre or a chilled Chardonnay. A bowl of creamy tomato bisque for the ultimate comfort food pairing. A light, chilled glass of sparkling cider.