- 8 slices bread (eggy)
- 2 pounds Parisian ham (thinly sliced)
- dijon mustard (As needed)
- 1/4 cup butter
- 2 tablespoons flour
- 4 cups milk
- 5 cups gruyere cheese (shredded, divided)
- salt (To taste)
- black pepper (To taste)
- nutmeg (To taste, whole)
- 1. Preheat a broiler or salamander. Over medium low heat, melt the butter in a saucepan. Add the flour and cook for a couple of minutes until the butter has stopped frothing and the roux begins to smell nutty. Slowly add the warm milk, whisking the entire time to prevent lumps from forming. Bring to a simmer and allow to cook for several minutes, stirring occasionally until the raw flour taste has cooked out. Add 1 cup of the shredded Gruyere cheese in increments, stirring to fully incorporate before the next addition. Season the mornay sauce with salt, black pepper and a few swipes on a microplane of whole nutmeg.
- 2. Spread a thin layer of Dijon mustard on each slice of bread. Place a few slices of ham over the bread, a bit of mornay sauce and repeat until you have a nicely mounded open-faced sandwich. Top with approximately ¼ cup of grated Gruyere.
- 3. Place the open-faced sandwiches under a broiler or salamander until bubbly and slightly browned.