Ingredients:
- 2.5 lbs (1.13 kg) Yukon Gold potatoes, peeled
- 2 cloves garlic, minced
- 2 cups (475 ml) heavy cream
- 1 cup (235 ml) whole milk
- 4 tbsp (57 g) unsalted butter, plus more for greasing dish
- 1/4 tsp freshly grated nutmeg
- 1/2 tsp dried thyme
- 1 cup (100 g) grated Gruyère cheese
- Salt and freshly ground black pepper to taste
- 1/4 cup grated Parmesan cheese (optional)
Instructions:
- Preheat oven to 375°F (190°C). Grease the baking dish.
- Slice the potatoes very thinly (about 1/8 inch or 3mm thick) using a mandoline or knife.
- In a large saucepan, melt butter over medium heat.
- Add minced garlic and cook until fragrant, about 30 seconds.
- Stir in heavy cream, milk, nutmeg, and thyme. Bring to a simmer, stirring occasionally.
- Season with salt and pepper to taste.
- Arrange a layer of potato slices in the prepared baking dish, slightly overlapping.
- Pour a thin layer of cream sauce over the potatoes, ensuring they are lightly coated.
- Repeat layers of potatoes and sauce until all potatoes are used, finishing with a generous layer of cream sauce.
- Cover the dish tightly with aluminum foil.
- Bake for 30 minutes.
- Remove the foil and sprinkle evenly with Gruyère cheese (and Parmesan if using).
- Bake uncovered for an additional 20-30 minutes, or until the potatoes are tender when pierced with a fork and the cheese is melted and golden brown.
- Let stand for 10 minutes before serving.