1.
2.
Add the butter, turn down the heat and wait for it to melt. Add the flour and cook for a few minutes.
3.
Pour in the warm milk, turn up the heat and continue cooking, stirring constantly. Once you have a béchamel with the desired texture, add salt and pepper to taste and then add the nutmeg.
4.
Spread the mixture into a baking dish. Crack the eggs on top. Sprinkle the cheeses over the top and add another pinch of salt. Heat under the broiler for a few minutes, until the cheese is melted and the eggs are cooked through.