INGREDIENTS
2 tbsp
butter
2 tbsp
flour
1 1/2 cups
milk
1 pinch
each of salt, freshly ground pepper, nutmeg, or more to taste
6 oz
Gruyère cheese, grated (about 1 1/2 cups grated)
1/4 cup
grated Parmesan cheese (packed)
8
slices of French or Italian loaf bread
12 oz
ham, sliced
Dijon mustard