Croque Madame

Makes 4 servings

5 tablespoons unsalted butter
3 tablespoons all-purpose flour
2 cups 2% or whole milk
1/4 teaspoon salt
1/8 teaspoon black pepper
1/8 teaspoon freshly grated nutmeg
1 1/2 cups coarsely grated Gruyere cheese
8 slices firm white sandwich bread
4 teaspoons Dijon mustard
8 slices cooked ham (preferably Black Forest)
4 large eggs

Make sauce:
Melt 3 tablespoons butter in a 1- to 1 1/2-quart heavy saucepan over moderately low heat, then whisk in flour and cook roux, whisking, 3 minutes. Whisk in milk and bring to a boil, whisking constantly. Reduce heat and simmer, whisking occasionally, 5 minutes. Whisk in salt, pepper, nutmeg, and 1/2 cup cheese until cheese is melted. Remove from heat and cover surface directly with a sheet of wax paper.

Make sandwiches:
Spread 1 1/2 tablespoons sauce evenly over each of 4 slices of bread, then sprinkle evenly with remaining cheese (1/4 cup per slice). Spread 1 teaspoon mustard evenly on remaining 4 bread slices and top with 2 slices of ham and invert onto cheese-topped bread to form sandwiches.

Preheat boiler

Butter top side of sandwiches and place butter-side down in 12-inch nonstick skillet over moderately low heat. Then butter top side in pan. Cook sandwiches, turning over once, until both sides are golden, 3 to 4 minutes total. Remove from heat and transfer sandwiches to baking pan, then wipe out skillet with paper towels.

Top each sandwich with 1/3 cup sauce, spreading evenly. Broil sandwiches 4 to 5 inches from heat until sauce is bubbling and golden in spots, 2 to 3 minutes. Turn off broiler and transfer pan to lower third of oven to keep sandwiches warm.

Heat remaining tablespoon butter in nonstick skillet over moderate heat until foam subsides, then crack eggs into skillet and season with salt and pepper. Fry eggs, covered, until whites are just set and yolks are still runny, about 3 minutes. Top each sandwich with a fried egg and serve immediately.

- Recipe adapted from www.epicurious.com