This Parisian café classic may be the ultimate ham and cheese sandwich: crisp, buttery, piled with salty, sweet ham and oozing with cheesy Mornay sauce.
For the Mornay sauce:
- 1 1/2 Tbs. unsalted butter
- 1 1/2 Tbs. all-purpose flour
- 1 cup (240 ml) milk
- 1 cup (115 g) grated Comté or Gruyère cheese
- 1/2 cup (55 g) grated Parmigiano-Reggiano cheese
- Pinch of freshly grated nutmeg
- Pinch of ground cayenne
- Fine sea salt, to taste
8 slices pain de mie or other good-quality sandwich bread
- 2 Tbs. unsalted butter, melted
- 1/2 cup (125 g) whole-grain mustard
- 1 lb. (450 g) boneless picnic ham or other cured ham, thinly
To make the Mornay sauce, in a small saucepan over medium heat, melt the butter. Whisk in the flour until combined and then cook and whisk for 1 minute. Slowly whisk in the milk, reduce the heat to low and cook, stirring constantly, until smooth and thick, about 5 minutes. Continue cooking and stirring for about 5 minutes more, allowing the sauce to further thicken, then remove from the heat. Stir in the cheeses, nutmeg and cayenne until the cheeses melt. Season with salt.
Preheat an oven to 450°F (230°C).
Lay the bread slices in a single layer on a baking sheet. Brush the slices with the butter, then flip them over, buttered side down. Spread the second side of each slice with the mustard. Spoon 2 Tbs. of the Mornay sauce on top of each of 4 slices. Top each of the remaining 4 slices with one-fourth of the ham, followed by 1 Tbs. of the sauce.
Transfer to the oven and bake until the sauce is bubbling and brown and the bottom of each bread slice is crisp and golden, 8 to 10 minutes. Remove the pan from the oven and, using a spatula, marry each of the ham-topped slices with a Mornay-topped slice. Serve immediately. Serves 4.
Adapted from In the Charcuterie, by Taylor Boetticher & Toponia Miller (Ten Speed Press, 2013).