Preheat the oven to 400°F/200°C/gas 6.
Butter an ovenproof baking dish.
Melt the
butter in a medium saucepan over low heat. Add
the flour and mix to form a paste.
Pour in the
milk, stirring constantly. Bring to a boil and
remove
from the heat.
Stir in half the Parmesan and nutmeg.
Arrange layers of the cheese sauce,
Fontina, and eggs in the prepared dish, finishing
with the cheese sauce. Sprinkle with the remaining
Parmesan.
Bake for
10-15
minutes, or until
golden and bubbling.
Serve hot.