This rich, cheesy dish is filled with butter, Gruyère cheese, and Parmesan cheese, and makes the perfect side for a festive Southern supper.
Mixed Potato Gratin
Serves: 8 to 10 servings
- 1½ pounds medium Yukon gold potatoes, peeled
- ½ pound medium sweet potatoes, peeled and halved lengthwise
- 1¾ cups heavy whipping cream
- ⅓ cup minced garlic
- ¼ cup unsalted butter, softened
- 1 tablespoon chopped fresh sage
- 2 teaspoons kosher salt
- 2 teaspoons chopped fresh thyme
- ½ teaspoon ground black pepper
- ¼ teaspoon ground nutmeg
- 1 cup shredded Gruyère cheese, divided
- ½ cup shredded Parmesan cheese
- Garnish: chopped fresh sage
- Preheat oven to 400°. Spray an 11×8-inch baking dish with butter-flavored cooking spray; place on a rimmed baking sheet. Fill a large bowl with cold water.
- Using a very sharp knife or a mandolin, slice potatoes crosswise into ⅛-inch-thick slices, adding slices to bowl of water as you go. Drain potatoes, and thoroughly pat dry. Tightly shingle half of potatoes evenly in bottom of prepared baking dish.
- In a medium saucepan, heat cream, garlic, butter, sage, salt, thyme, pepper, and nutmeg over medium heat just until bubbles form around sides of pan. (Do not boil.) Pour half of cream mixture all over potatoes in baking dish; sprinkle with ½ cup Gruyère. Shingle remaining potatoes onto cheese. Top with remaining cream mixture and remaining ½ cup Gruyère. Sprinkle with Parmesan. Cover with foil, poking holes in top with a wooden pick.
- Bake for 40 minutes. Uncover and bake until potatoes are tender and golden brown and sauce is bubbly, 25 to 30 minutes, recovering with foil to prevent excess browning, if necessary. Let stand for 30 minutes before serving. Garnish with sage, if desired.
Kitchen Tip: Be sure to use the cutting glove or hand guard that comes with your mandolin, and never let children use a mandolin.