Peel and slice your potatoes very thin. Use a mandoline for the best results. Aim for slices about one-eighth inch thick.

Heat the heavy cream in a small saucepan. Add the crushed garlic and a pinch of nutmeg. Let it simmer gently on low heat.

Place one layer of potatoes in the dish. Overlap the edges slightly to cover the bottom. Sprinkle a little salt and pepper on top.

Add a generous layer of shredded Gruyère cheese. Pour a bit of the warm cream mixture over. Repeat these layers until the dish is full.

Cover the baking dish tightly with aluminum foil. Bake in the oven for forty-five minutes. This allows the potatoes to become very soft.

Remove the foil and add more cheese. Bake for another thirty minutes without the cover. Wait for the top to turn golden brown.