CROQUE MONSIEUR

Steps:

• Make bechamel sauce: Melt butter in a small saucepan over medium heat until just starting to bubble. Add flour, and cook, whisking constantly, until smooth but not browned, about 3 minutes.
• Whisking constantly, slowly add milk; continue cooking while whisking until mixture has thickened, about 3 minutes more. Remove from heat, and add salt, nutmeg, cayenne, and black pepper. Transfer to a bowl; place plastic wrap directly on surface of sauce, and set aside.
• Heat broiler. Heat a griddle or large cast-iron skillet over medium-low heat. Smear one side of bread slices with mustard. Top 4 slices with a layer each of ham and cheese; cover with remaining 4 bread slices, pressing gently to adhere. Generously butter outer sides, spreading it all the way to the edges.
• Place sandwiches on griddle or in skillet. Cook until golden brown and cheese has melted, 3 to 4 minutes a side. Transfer to work surface; divide bechamel sauce evenly over tops, spreading to edges; sprinkle with grated cheese.
• Transfer to broiler, and cook until topping is melted and golden, 2 to 3 minutes. Serve immediately.