Potato, Gruyère, and Caramelized Onion Gratin
Indulge in the ultimate comfort food with our potato, Gruyere, and caramelized onion gratin.
Our potato, Gruyère, and caramelized onion gratin is a comforting and satisfying side dish. The dish pairs russet potatoes with the rich nuttiness of Gruyère cheese and the subtle sweetness of caramelized onions. Fresh garlic and a blend of thyme, rosemary, and sage add warmth, creating an aromatic and satisfying dish. This delicious side dish is sure to impress, perfect for holidays or any special occasion. If you’re looking for a crave-worthy side dish for your feast, this potato gratin will not disappoint.
Why You’ll Love It
Rich and savory layers. Nutty Gruyère, sweet caramelized onions, and creamy potatoes come together in perfect harmony.
Perfect for holidays. This gratin makes an elegant side dish for Thanksgiving, Christmas, or any special gathering.
Surprisingly flexible. Easy to adapt with different cheeses, herbs, or even additional vegetables like mushrooms or leeks.
Make-ahead friendly. You can prep and bake it in advance, then reheat when it’s time to serve.
Ingredient Notes
- Russet potatoes: Starchy and sturdy, these slice cleanly and hold their shape while absorbing the herbed cream.
- Gruyère cheese: Adds rich, nutty depth. For a twist, try smoked Gouda or Comté.
- Caramelized onions: Cooked low and slow until golden, they bring a natural sweetness that balances the dish.
- Herbs and garlic: Fresh thyme, rosemary, and sage add aromatic warmth. Use dried herbs if fresh aren’t available.
- Heavy cream: Simmered briefly with garlic and herbs to infuse flavor into every bite.
Steps to Make Potato, Gruyère, and Caramelized Onion Gratin
- Caramelize the onions slowly in butter and olive oil until soft and golden. A splash of water helps if they start to stick.
- Simmer the cream with garlic and herbs to build flavor. Taste and season it generously before adding the potatoes.
- Layer the sliced potatoes in the buttered dish with caramelized onions and Gruyère cheese. Press down lightly and pour the hot cream over everything.
- Top with remaining cheese and bake covered until tender. Uncover and bake a bit longer to get a golden, bubbly crust.
- Let the gratin rest for 10 minutes before serving so the layers settle and slice cleanly.
Recipe Variations
- Smoky Twist: Swap half of the Gruyère cheese for smoked Gouda or cheddar and add a dash or two of smoked paprika.
- Sliced Vegetables: Layer in some thinly sliced vegetables, such as fennel or parsley.
- Mushrooms: Add a few layers of sliced sautéed mushrooms to the gratin.
- Herbs: Use dried herbs or an herb blend instead of fresh.
- Onions: Replace the caramelized onions with sautéed leeks or shallots.
- Mustard: Add 1 teaspoon of mustard to the cream mixture for a hint of sharpness.
- Bacon: Add smoky flavor with a few strips of cooked and crumbled bacon.
What to Serve With Potato Gratin
- Grilled Sausages: Grilled or baked Italian sausages can add a rustic, smoky flavor to the creamy potatoes.
- Sautéed Vegetables: Spinach, broccolini, or garlicky kale contrast nicely with the creamy gratin.
- Roasted Vegetables: Brussels sprouts, butternut squash, asparagus, or carrots can add caramelized sweetness and color.
- Meats: The rich potato dish pairs well with roasted chicken, turkey, pork, lamb, or beef.
- Fish: Grilled or baked fish would also be excellent. This baked Chilean sea bass with lemon butter sauce would be fabulous with the gratin, or pair it with panko-crusted salmon.
How to Store and Reheat
Refrigerate: Cover tightly or transfer to an airtight container and store in the refrigerator for up to 4 days.
Freeze? Not ideal, as the cream may separate, but individual portions can be wrapped and frozen for up to 1 month. Thaw overnight in the fridge.
To Reheat: Warm in a 325°F oven, loosely covered with foil, until heated through. Add a splash of cream if it seems dry. Individual portions can also be microwaved.
Potato, Gruyère, and Caramelized Onion Gratin
Ingredients
- 2 tablespoons unsalted butter
- 1 1/2 tablespoons olive oil
- 2 medium yellow onions, thinly sliced
- Kosher salt and freshly ground black pepper
- 1 1/2 cups heavy cream
- 1 teaspoon garlic, minced
- 1 teaspoon thyme, fresh chopped
- 1 teaspoon rosemary, fresh chopped
- 1 1/2 teaspoons sage, dried rubbed
- 2 1/2 to 3 pounds russet potatoes, peeled and sliced about 1/3-inch thick
- 2 cups Gruyere cheese, shredded
- 1/2 cup grated Parmesan cheese
Instructions
Caramelize the Onions
- Heat the butter and oil in a large skillet over medium heat. When the butter has melted, add the onions and a dash each of salt and pepper. Cook, stirring frequently, for 4 to 6 minutes or until the onions begin to brown in spots. Turn the heat to low, cover the skillet, and cook, stirring occasionally, for 15 minutes or until soft and golden brown. Add a splash of water or stock as needed.
Prepare the Gratin
- Heat the oven to 400°F and butter an 11-inch gratin dish or 2-quart casserole.
- Combine the cream, garlic, herbs, and a dash of each salt and pepper in a large saucepan, then place it over medium heat. Heat just until it starts to boil. Remove from the heat, taste, and add salt and pepper as needed. Add the sliced potatoes to the cream mixture.
- Arrange about 1/3 of the potato slices in a slightly overlapping layer in the gratin dish. Sprinkle generously with salt and pepper. Top with half of the caramelized onions and 1/3 of the Gruyère. Repeat with another 1/3 of the potatoes, salt and pepper, the remaining caramelized onion, and another 1/3 of Gruyère. Finish with a layer of the remaining potatoes, salt, and pepper. Press the potatoes down and add the remaining cream mixture. Sprinkle with the remaining Gruyère and Parmesan.
- Cover the gratin dish with foil and bake for 45 minutes. Remove the foil and bake for 20 minutes or until the top is golden brown and the potatoes are fork-tender.
- Remove the gratin to a rack and let it stand for 10 minutes before serving. Enjoy!
Nutrition
Disclaimer:
Our nutritional information is based on a third-party application that analyzes the ingredients list to determine the values. The information is meant to be helpful, but should be considered an estimate. Values may differ depending on measurements, brands, serving variations, and database availability.
