Prep time: 20 minutes
Total time: 20 minutes
for the béchamel sauce:
1 1/2 cups whole milk
3-4 tablespoons unsalted butter, divided
2 tablespoons all-purpose flour
Nutmeg (fresh grated or powdered)
kosher salt, to taste
for the sandwich:
2 slices of rustic country bread
1 tablespoon Dijon mustard
2–3 slices of Gruyère
3–4 slices of ham
½ cup of shredded Gruyère
1 large egg
1. Begin by preparing your béchamel sauce. Heat milk in a saucepan and in a separate saucepan, melt 1 tablespoon of the butter. Once milk is warm and butter is melted, add flour to butter and whisk for a minute or two. Slowly add milk to butter-flour while whisking continuously until all milk is added and sauce is smooth and lump-free. Bring to a boil, but them bring to a simmer for a few minutes. Season with salt and a pinch of nutmeg and cook down for a few minutes, then set aside.
2. Spread a very thin layer of Dijon mustard on both slices of bread, then add sliced Gruyère on each side and ham in the middle. Melt a pat of butter on your griddle or skillet over medium heat, and grill assembled sandwich until cheese is melted and both sides of the bread are toasty and delicious. Spread béchamel on top of the sandwich and heap shredded Gruyere on top all the way to the edge of the bread. Place in the broiler until cheese is melted and caramelized – but don't let it burn!
3. Meanwhile, heat ½ tablespoon butter in a small skillet or egg pan over medium heat. Gently crack egg into the pan, being careful not to break the yolk. Cook until white is just done and not snotty. Sprinkle with salt and place on top of the sandwich. Voilà and bon appetit!