# [[Cheesy Hasselback Potato Gratin]] **Prep Time:** **20 minutes** **Cook Time:** **90 minutes** **Yield:** 4–6 servings ## Ingredients - 3 oz (85 g) finely grated Gruyère or Comté cheese - 2 oz (60 g) finely grated Parmigiano-Reggiano cheese - **(Reserve 1/3 of the combined cheese mixture for finishing.)** 👀 - 2 cups (480 ml) heavy cream - 1 tablespoon fresh thyme leaves, roughly chopped - 2 medium cloves garlic, minced - Kosher salt and freshly ground black pepper - 3 to 3½ lb (1.4–1.6 kg) russet potatoes, peeled and sliced **1/8-inch (≈3 mm)** thick on a mandoline (5–6 medium potatoes) - 2 tablespoons (30 g) unsalted butter, plus more for greasing the dish *Special equipment: - *2-quart baking dish - *mandoline ## Instructions 1. Adjust oven rack to middle position and preheat oven to ==**400°F (205°C)**==. Grease a 2-quart baking dish with butter. 2. Combine both grated cheeses in a large bowl. Transfer **⅓ of the cheese mixture** to a separate small bowl and set aside. Add the heavy cream, thyme, and minced garlic to the remaining cheese; season generously with salt and pepper. Toss the potato slices in the cream/cheese mixture with your hands until every slice is coated and separated so the cream can get between them. 3. Pack the coated potato slices upright into the prepared dish, edges aligned vertically, working around the perimeter and into the center until very tightly packed. If needed, slice an extra potato, coat, and add to fill gaps. Pour any excess cream/cheese mixture evenly over the potatoes until it comes about halfway up the sides of the dish (you may not need all the liquid). 4. Cover the dish tightly with foil and transfer to the oven. Bake, covered, for **30 minutes**. 5. Remove foil and continue baking until the top is pale golden, about **30 minutes** longer. Remove from oven, sprinkle with the reserved cheese, and return to the oven. Bake until the top is deep golden brown and crisp, about **30 minutes** longer. 6. Remove from oven, let rest for **a few minutes**, then serve warm. #### Notes - Potato shapes vary; longer/thinner potatoes pack differently than short/round ones. Buy a few extras to ensure the dish fills. You may not need all the cream mixture depending on exact potato size and dish. - To scale down, divide ingredients by two and use a 10-inch skillet.