Pumpkin Potato Gratin
A creamy, cheesy gratin featuring tender potatoes and a lightly spiced pumpkin sauce, layered with sharp Cheddar and Gouda for a comforting, fiber-rich side dish. Perfect for weeknight dinners, holiday meals, or make-ahead prep.
Equipment
- 2-quart baking dish, lightly buttered
- Medium saucepan
- Whisk
- Knife and cutting board
- Measuring Cups and Spoons
- Aluminum foil, coated with cooking spray
Ingredients
- 2 tablespoons unsalted butter plus extra for greasing
- 2 cloves garlic minced (about 1 tablespoon)
- 2 tablespoons all-purpose flour
- 1 cup whole milk
- ½ teaspoon kosher salt plus extra to taste
- ⅔ cup canned pumpkin purée not pumpkin pie filling
- ½ teaspoon granulated sugar
- ⅛ teaspoon cayenne pepper
- Freshly ground black pepper to taste
- 2 pounds russet potatoes about 2–3, peeled and sliced 1/8 inch thick
- ¾ cup shredded sharp Cheddar cheese
- ¾ cup shredded Gouda cheese
- 1 tablespoon fresh thyme leaves for garnish
Instructions
- Preheat and Prepare Baking Dish: Begin by preheating your oven to 375°F (190°C). While the oven warms, lightly butter a 2-quart baking dish to ensure the gratin doesn’t stick and will develop a beautiful golden crust. Set the dish aside so it’s ready when your layers are complete.
- Melt Butter and Infuse Garlic: Place a medium saucepan over medium heat and add 2 tablespoons of unsalted butter. Allow it to melt completely, then add the minced garlic. Cook, stirring frequently, for 1 to 2 minutes until the garlic becomes fragrant and slightly softened. This step releases the garlic’s natural sweetness without burning it, creating a flavorful base for your pumpkin sauce.
- Make the Roux: Sprinkle 2 tablespoons of all-purpose flour over the melted butter and garlic. Stir continuously for about 1 minute to cook out the raw flour taste while forming a smooth, golden roux. This mixture is the foundation for your creamy pumpkin sauce, ensuring it thickens evenly without lumps.
- Add Milk and Season: Slowly pour 1 cup of whole milk into the roux in a steady stream, whisking constantly. This gradual incorporation prevents clumps and creates a silky sauce. Once the milk is fully combined, whisk in 1/2 teaspoon kosher salt. Bring the mixture to a gentle boil, then reduce the heat to maintain a simmer. Allow it to thicken for 1 to 2 minutes, stirring occasionally to achieve a smooth consistency.
- Incorporate Pumpkin and Spices: Remove the saucepan from the heat and stir in 2/3 cup canned pumpkin purée, 1/2 teaspoon sugar, and 1/8 teaspoon cayenne pepper. Taste the sauce and adjust seasoning with freshly ground black pepper and additional salt if needed. The pumpkin adds a subtle sweetness, natural fiber, and beautiful autumnal color, while the cayenne provides a gentle warmth that enhances the cheesy layers.
- Slice Potatoes: While your sauce cools slightly, peel 2 pounds of russet potatoes and slice them into 1/8-inch (3 mm) thick rounds. A sharp knife or mandoline works best to create even slices, which ensures uniform cooking and a visually appealing layered gratin.
- Layer Potatoes and Sauce: Start the layering process by arranging one-third of the potato slices in the prepared baking dish, slightly overlapping each slice. Lightly season with salt and freshly ground black pepper. Spread one-third of the pumpkin sauce evenly over the potatoes. Sprinkle 1/4 cup each of Cheddar and Gouda cheese over the sauce. Repeat this layering process two more times, finishing with a layer of cheese on top. A tester tip: divide the potatoes into three equal piles to make layering easy and precise.
- Cover and Bake: Coat a piece of aluminum foil with cooking spray and cover the baking dish. Bake in the preheated oven for 70 to 90 minutes, or until the potatoes are tender when pierced with a knife. Baking covered ensures the potatoes cook evenly and the sauce remains creamy without drying out.
- Broil for Golden Top: Once the potatoes are fully cooked, remove the foil and switch the oven to broil. Place the dish back in the oven uncovered for 2 to 3 minutes, watching closely, until the top is beautifully browned and slightly mottled. The broiling step creates a crunchy, cheesy crust that contrasts perfectly with the soft, creamy layers beneath.
- Rest, Garnish, and Serve: Remove the gratin from the oven and allow it to rest for 10 minutes. This resting period helps the sauce set slightly, making it easier to serve. Garnish with 1 tablespoon of fresh thyme leaves for a pop of color and aromatic freshness. Serve warm as a comforting side dish for family dinners, holiday gatherings, or meal-prep-friendly lunches.
Notes
- Use uniform potato slices to ensure even cooking; a mandoline slicer works best for consistency.
- You can substitute Gouda with more Cheddar or Fontina for a slightly different flavor profile.
- For a spicier kick, add a pinch more cayenne pepper or a few dashes of smoked paprika.
- The gratin can be made a day ahead; keep it covered in the refrigerator and bake before serving.
- Leftovers reheat well in the oven at 350°F (175°C) for 15–20 minutes or in the microwave for a quicker option.
