Preheat your oven to 375°F (190°C).
Prepare the baking dish by greasing it with butter.
In a saucepan over medium heat, melt the butter and sauté the minced garlic for 1–2 minutes until fragrant.
Add heavy cream and milk to the saucepan. Sprinkle in the salt, pepper, and nutmeg, then stir to combine.
Layer half of the sliced potatoes in the prepared baking dish, followed by half of the cheese, and then pour half of the creamy mixture over it.
Repeat the layers with the remaining potatoes, cheese, and creamy mixture.
Cover the baking dish with foil and bake for 45 minutes.
Remove the foil and bake for an additional 20 minutes until the top is golden brown and bubbly.
Let the dish sit for 10 minutes before serving.