Yield: 2 servings
- 1-1/2 teaspoons butter
- 1-1/2 teaspoons all-purpose flour
- 3 fluid ounces whole milk
- Pinch kosher salt
- 1/2 teaspoon dijon style mustard, plus additional for sandwiches
- Pinch fresh grated nutmeg
- 1 tablespoon grated Parmigiano or other grana cheese
- 3 ounces shredded Gruyere or Emmentaler cheese, divided (about 1 cup total)
- 4 slices firm white bread
- 4-6 tablespoons unsalted butter, very soft
- 4 ounces thin sliced ham
2. For the mornay sauce, melt the butter in a small saucepan over medium heat and cook briefly until it has mostly stopped foaming. Add the flour and cook for a few minutes until the mixture browns slightly. Add the milk and whisk to combine into a smooth sauce. Cook for a few minutes more, until sauce has thickened, then stir in nutmeg, 1/2 teaspoon mustard and a pinch of salt. Stir in the Parmigiano and 1 tablespoon of the Gruyere. Keep warm.
3. Heat a griddle or large skillet over medium low heat. Spread one side of each piece of bread with butter and place on the griddle buttered side down. Butter the exposed sides of the bread. When the bottom sides of the bread slices are golden brown, flip them over to cook the other side. While the second side is cooking, spread a little dijon mustard on two slices of the bread. Top the other two slices with about 1/3 cup per slice of the grated Gruyere and layer the ham evenly over the cheese (don't use all the cheese; you'll need more to top the sandwich).
4. When the bottom sides of the bread are golden brown, assemble the sandwiches by placing one of the slices with mustard over a slice with ham and cheese. Place the sandwiches on the rack. Spread about half of the bechamel over each sandwich. You want the bread covered with an even layer, but not too thick; depending on the size of your bread, you may not need all of the sauce. Sprinkle the remaining cheese over the bechamel.
5. Place the pan in the oven and bake for 5-10 minutes, or until the ham and cheese inside are heated through and the cheese is melted.
6. Turn the oven to the broiler setting. Broil the sandwiches until the top is bubbling and lightly browned. Remove from the oven and let cool for a minute before slicing.