Preheat the oven to 180°C (approximately 350°F).
Peel the garlic and rub over the baking dish. Rinse the potatoes, peel and cut into very thin slices. Layer the potatoes in the baking dish. Mix the cream, milk, cheese and creme fraiche. Season with salt, pepper and nutmeg. Pour the cream over the potatoes, so that the potatoes are barely covered.
Bake for 40-50 minutes, until golden brown. Serve sprinkled with rosemary and red pepper flakes.