Preheat the oven to 150°C.
Cut the potatoes into thin slices.
Mix the cream and milk and bring to the boil. Season and add the nutmeg.
Rub the baking dish with the peeled garlic clove.
Place the potatoes slices in the baking dish, cover with the cream and milk mixture and the Mix Mozzarella, Cheddar, Maasdam Maestrella.
Bake for 1h45, keeping an eye on the oven.
The gratin is cooked when it is golden brown and a knife can be inserted without resistance.