Croissant Croque Monsieur

• ½ c butter, divided
• 3 tbsp flour
• 1.5 c warm milk
• Kosher salt and freshly ground black pepper to taste
• 2 grates of fresh nutmeg (or 1 pinch ground nutmeg)
• 4 croissants
• 4 tsp dijon mustard
• ¾ lb thinly sliced Black Forest ham (8-12 slices)
• 10 oz shredded gruyere or appenzeller cheese, divided

Preheat oven to broil and place oven rack in middle of oven, 8-10 inches from the top heat source.

Make the bechamel sauce Heat 3 tablespoons butter in a medium saucepan over medium heat until melted. Whisk in flour and cook, stirring constantly, for about 1 minute. Slowly add warm milk in a thin stream while continuously whisking. Season with salt, pepper and nutmeg and continue cooking, whisking constantly and using a rubber spatula to occasionally scrap the bottom of the saucepan, about 3-4 minutes until sauce thickens. Remove from heat and place a piece of plastic wrap directly on surface to prevent a skin from forming.

Make the sandwich Using a serrated knife, slice each croissant in half lengthwise. Spread Dijon mustard on bottom half of each croissant and add 2-3 slices of ham on top. Spread bechamel on inside top halves of each croissant, then sprinkle with cheese, reserving about ½ cup of the cheese. Close the sandwiches.

Heat 2-3 tbsp butter in a large skillet or cast-iron pan over medium heat until melted. Add sandwiches, toasting in batches if necessary, pressing gently. Turn heat to medium-low and top each sandwich with remaining cheese. Cover with a lid and cook, 4-5 minutes, until cheese is melted, turning heat to low if necessary to prevent bottoms from burning.

Place toasted sandwiches on a sheet pan and spoon remaining bechamel sauce on top of sandwiches. Place in oven and broil for 45 seconds to 1 minute until sauce is bubbly; watch carefully so as not to burn the tops of the croissants. Serve immediately.