Classic Croque Monsieur Sandwich Recipe

Fans of a simple grilled cheese sandwich are guaranteed to like this elevated French version of the classic dish: a croque monsieur. With the addition of ham and béchamel sauce, this savory bite showcases basic ingredients in a dazzling light. While this traditional recipe has plenty of spin-offs (including the croque madame, with an), a classic croque monsieur is a must for any cheese lover's repertoire.

Recipe developer Alexander Roberts brings us the perfect recipe for this French bistro favorite that will satisfy all your cheesy desires in under half an hour. He shares, "I love making a croque monsieur when I'm craving a classic ham and cheese, but also want to make something a little more involved. It's quick, easy, and delicious!" The classic ingredients and salty flavor profile come together in this carefully executed recipe, for a hearty sandwich you'll want to serve for breakfast, brunch, lunch, and yes, even dinner.

To make this classic croque monsieur recipe, you'll need unsalted butter, all-purpose flour, whole milk, ground nutmeg, kosher salt, Dijon mustard, and shredded Gruyère cheese. For the assembly, cut thick slices of bread — Roberts recommends pain de mie (a soft bread) or sourdough. Then, pick up sliced deli ham and sliced Gruyère cheese. If you're having trouble sourcing the right cheese, Roberts says that "Swiss or Emmental cheese would be a great substitute for Gruyère."

Begin by preheating the oven to 425 F and placing tin foil over a small baking sheet to line it. Grease the foil lightly with cooking spray, then set the tray aside. Roberts explains that "making bechamel requires cooking a light roux first with butter and flour." Start by adding the butter to a small pot and placing it on a burner over medium heat. Melt the butter then whisk in the flour while you cook the mixture for 1 minute. 

While you keep whisking the mixture, slowly pour in the milk. Bring the contents to a low boil for 3 to 5 minutes as you continue to whisk until the consistency is very thick. At this point, remove the pot from the burner and whisk in the ground nutmeg, salt, Dijon mustard, and shredded cheese.

To assemble the sandwiches, place the four slices of bread on the tin foil-lined baking sheet. Spread the béchamel evenly over all the pieces, then place two slices each of ham and cheese onto two slices of bread. Top the stacks with the other pieces of toast, ensuring the béchamel side is on top. Sprinkle some extra shredded cheese over the top slices.

Once the oven is at temperature, bake the croque monsieur sandwiches for 10 minutes to start. Turn the setting to high broil and cook for 1 to 2 minutes until the cheese is bubbly with brown spots over the surface. Serve the piping hot sandwiches immediately. 

"Croque monsieur goes perfectly with a side of lightly dressed green salad — a great counter to the rich, cheesiness of the sandwich," Roberts comments. "This sandwich should be served and eaten fresh," he adds but notes, "If you'd like to prep ahead, the béchamel can be prepared in advance and kept in the fridge until ready to assemble."