1. Preheat oven to 375°F (190°C).
2. In a saucepan, melt butter over medium heat. Add garlic and onion, sautéing until translucent.
3. Add heavy cream, nutmeg, salt, and pepper. Bring to a simmer and remove from heat.
4. Layer half of the potato slices in a greased baking dish. Pour half of the cream mixture over the potatoes. Sprinkle half of both cheeses over the top.
5. Repeat with the remaining potatoes, cream mixture, and cheese.
6. Cover with aluminum foil and bake for 60 minutes. Remove the foil and bake for an additional 15 minutes or until the top is golden and crispy.
7. Garnish with fresh thyme leaves before serving.
Prep Time: 20 minutes | Cooking Time: 75 minutes | Total Time: 95 minutes
Kcal: 520 kcal | Servings: 6 servings