Classic French gratin: sliced potatoes slowly baked in garlic-infused double cream and milk until rich, bubbling, and tender throughout, with a natural caramelized top.
Slice potatoes 3mm thin. Do not rinse, as natural starch thickens the cream.
Rub baking dish with garlic clove and butter. Heat cream, milk, remaining garlic, nutmeg, salt, and pepper in a saucepan until warm.
Arrange sliced potatoes in overlapping layers in the dish. Pour warm cream mixture over.
Bake at 160°C for 1 hour 15 minutes until potatoes are meltingly soft and top has a golden crust.