Golden, bubbly, and stuffed with melted cheese and savory ham, these classic oven-baked Croque Monsieur sandwiches are pure comfort food perfection passed down through generations.
Why You’ll Love This Recipe
Crowd Favorite: Baked all together on a single sheet pan for easy entertaining or family dinners.
Ultra Melty: Layers silky Béchamel white sauce with rich Gruyère cheese inside and out.
Golden & Crispy: Baking creates a crisp, golden-crusted crust without frying individual sandwiches.
Essential Kitchen Equipment
Baking Sheet & Parchment Paper: Keeps cheese from sticking and makes cleanup easy.
Small Saucepan & Whisk: For making a smooth Béchamel sauce.
Pastry Brush or Spatula: To spread sauce evenly over bread slices.
Ingredients
For the Béchamel (White Sauce):
2 tbsp Butter
2 tbsp All-purpose flour
1 1/4 cups Warm whole milk
1 pinch Nutmeg (grated)
1/2 tsp Dijon mustard
Salt & black pepper (to taste)
For the Sandwiches:
12 slices Thick white bread or brioche (6 sandwiches total)
6 to 8 slices Quality deli ham
2 1/2 cups Gruyère or Swiss cheese (shredded)
2 tbsp Dijon mustard (for spreading)
2 tbsp Butter (softened, for spreading on bread)
Step-by-Step Instructions
1. Preheat & Prep: Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper. Lightly butter one side of each bread slice.
2. Make Béchamel Sauce: Melt 2 tbsp butter in a small saucepan over medium heat. Whisk in 2 tbsp flour and cook for 1 minute. Gradually whisk in warm milk until smooth. Cook stirring constantly for 3 to 4 minutes until thickened. Remove from heat and whisk in Dijon mustard, nutmeg, salt, and pepper.
3. Assemble Sandwiches: Arrange 6 slices of bread buttered-side down on the baking sheet. Spread a thin layer of Dijon mustard on top, then add a layer of shredded Gruyère cheese and slices of ham.
4. Top & Smother: Place the remaining 6 bread slices on top. Spread a generous layer of Béchamel sauce over the top slice of each sandwich, then top with a heavy heap of remaining shredded Gruyère cheese.
5. Bake & Broil: Bake for 12 to 15 minutes until the sandwiches are hot and the cheese is melted. Switch to broil for 2 to 3 minutes until the top cheese layer turns golden brown and bubbly. Serve warm!
Chef’s Tips
Don’t Skimp on the Top Sauce: Spreading Béchamel over the top slice before adding cheese keeps the top bread moist and allows the cheese to melt into a rich, golden crown.
Cheese Selection: Gruyère is traditional for its rich nutty flavor, but a mix of Swiss and Mozzarella works great too!
Nutritional Breakdown (Per Sandwich / 6 Servings Yield)
Servings: 6 sandwiches
Calories: ~420 kcal
Protein: 22g
Net Carbs: 28g
Fat: 24g
Frequently Asked Questions (FAQ)
Can I make these ahead of time?
Yes! Assemble the sandwiches fully on the baking sheet, cover, and chill in the fridge for up to 24 hours. Bake directly from the fridge, adding a few extra minutes to the total baking time!