Preheat your oven to 375 F (190 C).
Peel and thinly slice the potatoes. A mandoline slicer is handy for achieving uniform thickness.
In a saucepan, combine the heavy cream, milk, minced garlic, salt, and pepper. Warm the mixture over medium heat until it's just about to simmer. Be cautious not to boil.
Grease a baking dish and arrange a layer of sliced potatoes. Pour a portion of the warm cream mixture over the potatoes. Repeat the layering process until you've used all the potatoes, ensuring the top layer is coated with the cream mixture.
Grate a bit of nutmeg over the top if using and sprinkle with additional salt and pepper. If desired, add a layer of grated Gruy re or Emmental cheese for a golden crust. Bake in the preheated oven for approximately 60-70 minutes, or until the potatoes are tender and the top is golden brown.
Allow the Potato Gratin to rest for a few minutes before serving. This allows the cream to set, creating a creamy and luscious texture.
