Preheat your oven to 375°F (190°C). Grease a baking dish with butter.

In a saucepan, heat the heavy cream over medium heat. Add the minced garlic, thyme, parsley, nutmeg, salt, and pepper. Stir and heat until the mixture is warm but not boiling, then remove from heat.

Arrange half of the thinly sliced potatoes in the greased baking dish in an even layer.

Pour half of the cream mixture over the potatoes and sprinkle with half of the shredded cheese.

Add the remaining potato slices in another even layer. Pour the rest of the cream mixture on top and sprinkle with the remaining cheese.

Cover the dish with foil and bake in the preheated oven for 45 minutes.

Remove the foil, add extra cheese on top if desired, and bake for an additional 15-20 minutes, or until the top is golden and the potatoes are tender.

Let the gratin cool for 5 minutes before serving. Garnish with fresh herbs if desired.