Cheesy Root Vegetable Gratin brings tender layers of root vegetables together with a creamy sauce and a golden, bubbling cheese topping. I love serving it as a cozy Thanksgiving side dish, especially when the holiday table needs something hearty and colorful.
Why You’ll Love This Cheesy Root Vegetable Gratin
This gratin makes simple root vegetables feel special, with sweet, earthy flavors in every forkful. It can be assembled ahead, then baked until tender and golden while you finish preparing the rest of the meal. A blend of cheeses adds savory richness without hiding the vegetables.
Cheesy Root Vegetable Gratin Ingredients & Substitutions
- 1 pound Yukon Gold potatoes, peeled and thinly sliced
- 1 pound sweet potatoes, peeled and thinly sliced
- 1 pound parsnips, peeled and thinly sliced
- 1 pound carrots, peeled and thinly sliced
- 2 tablespoons unsalted butter, plus extra for greasing the baking dish
- 2 cloves garlic, minced
- 1 1/2 cups heavy cream
- 1 cup whole milk
- 1 teaspoon fresh thyme leaves, or 1/2 teaspoon dried thyme
- 1 teaspoon kosher salt
- 1/2 teaspoon freshly ground black pepper
- 1/8 teaspoon ground nutmeg, optional
- 1 1/2 cups grated Gruyere cheese, divided
- 1/2 cup finely grated Parmesan cheese
Swap in turnips or celery root for some of the parsnips if you like. Gruyere gives the gratin a nutty flavor, while sharp white cheddar makes a tasty alternative. A mandoline makes even slices, but a sharp knife works well too.
Step-by-Step Instructions to Make Cheesy Root Vegetable Gratin
1. Prepare the oven and baking dish
Heat the oven to 375°F. Butter a 9-by-13-inch baking dish. Arrange the sliced vegetables nearby so you can layer them easily.
2. Make the cream mixture
Melt the butter in a small saucepan over medium-low heat. Add the garlic and cook for about 30 seconds, just until fragrant. Stir in the heavy cream, milk, thyme, salt, pepper, and nutmeg, then warm gently. Do not bring the mixture to a boil.
3. Layer the vegetables and cheese
Arrange the potato, sweet potato, parsnip, and carrot slices in overlapping layers in the baking dish. Pour the warm cream mixture evenly over the vegetables. Sprinkle 1 cup of the Gruyere and all of the Parmesan over the top.
4. Bake until tender
Cover the dish tightly with foil and bake for 45 minutes. Remove the foil, sprinkle on the remaining 1/2 cup Gruyere, and bake for another 25 to 30 minutes, until the vegetables are tender and the top is deeply golden. If a knife meets resistance, continue baking for a few more minutes.
5. Rest and serve
Let the gratin rest for 10 to 15 minutes before serving. This gives the cream time to settle and makes it easier to scoop neat portions.
Tips for Success
- Slice the vegetables to a similar thickness so they cook evenly.
- Warm the cream mixture before pouring it over the layers. It helps the gratin heat more evenly in the oven.
- Cover the dish for the first part of baking to soften the vegetables, then uncover it to brown the cheese.
- Let the finished gratin rest before serving so the sauce thickens slightly.
- Oven times can vary with slice thickness, so check the vegetables with a thin knife before taking the dish out.
Variations of Cheesy Root Vegetable Gratin
For a more savory flavor, add a thinly sliced yellow onion between the vegetable layers. A little chopped fresh rosemary can stand in for thyme, or add a pinch of smoked paprika for gentle warmth. To make the top extra crisp, mix the Parmesan with 1/3 cup of plain breadcrumbs before sprinkling it over the gratin.
Serving Suggestions: What to Pair with Cheesy Root Vegetable Gratin
Serve this gratin alongside roast chicken, roast turkey, or a hearty lentil loaf. It also pairs beautifully with green beans, Brussels sprouts, or a crisp salad dressed with a tangy vinaigrette. For a Thanksgiving spread, set it beside other vegetable sides and a warm bowl of gravy.
Storage & Reheating Instructions
Cool leftovers, cover the dish, and refrigerate for up to 4 days. Reheat individual portions in the microwave, or warm the covered baking dish in a 350°F oven until hot throughout. Remove the cover for the last few minutes if you would like to refresh the golden top. To prepare ahead, assemble the gratin, cover, and refrigerate for up to 1 day. Let it sit at room temperature while the oven heats, then bake until bubbling and tender, allowing extra time as needed.
Memories Made Around the Table
I love how a bubbling gratin invites everyone to linger at the table for one more scoop. The mix of sweet root vegetables and savory cheese feels right at home among Thanksgiving favorites, and it is the kind of side dish I look forward to sharing year after year.
FAQs
Can I make Cheesy Root Vegetable Gratin ahead?
Yes. Assemble it up to 1 day ahead, cover it, and refrigerate. Bake it when you are ready, allowing extra time if it is still cold from the refrigerator.
How do I know when the vegetables are cooked?
Slide a thin knife into the center of the gratin. The vegetables are ready when the knife passes through the layers easily.
Can I use different root vegetables?
Yes. Turnips and celery root work well in place of some of the potatoes, parsnips, or carrots. Keep the total amount of vegetables close to 4 pounds and slice them evenly.
Can I freeze leftovers?
You can freeze portions in an airtight container, though the creamy sauce may change texture slightly after thawing. For the best texture, enjoy refrigerated leftovers within 4 days.
Final Thoughts
With tender layers, a creamy center, and a beautifully browned cheese topping, Cheesy Root Vegetable Gratin is a comforting addition to a Thanksgiving table. Prepare it for a holiday gathering or serve it whenever you want a satisfying vegetable side.
Cheesy Root Vegetable Gratin
Equipment
- 1 9-by-13-inch baking dish
- 1 Small saucepan
- 1 Aluminum foil
Ingredients
- 1 pound Yukon Gold potatoes peeled and thinly sliced
- 1 pound sweet potatoes peeled and thinly sliced
- 1 pound parsnips peeled and thinly sliced
- 1 pound carrots peeled and thinly sliced
- 2 tablespoons unsalted butter plus extra for greasing the baking dish
- 2 cloves garlic minced
- 1.5 cups heavy cream
- 1 cup whole milk
- 1 teaspoon fresh thyme leaves or 1/2 teaspoon dried thyme
- 1 teaspoon kosher salt
- 0.5 teaspoon freshly ground black pepper
- 0.125 teaspoon ground nutmeg optional
- 1.5 cups Gruyere cheese grated and divided
- 0.5 cup Parmesan cheese finely grated
Instructions
- Heat the oven to 375°F. Butter a 9-by-13-inch baking dish. Arrange the sliced vegetables nearby.
- Melt the butter in a small saucepan over medium-low heat. Add the garlic and cook for about 30 seconds, until fragrant. Stir in the heavy cream, milk, thyme, salt, pepper, and nutmeg. Warm gently without bringing the mixture to a boil.
- Arrange the potato, sweet potato, parsnip, and carrot slices in overlapping layers in the baking dish. Pour the warm cream mixture evenly over the vegetables. Sprinkle 1 cup of the Gruyere and all of the Parmesan over the top.
- Cover the dish tightly with foil and bake for 45 minutes. Remove the foil, sprinkle on the remaining 1/2 cup Gruyere, and bake for another 25 to 30 minutes, until the vegetables are tender and the top is deeply golden. If a thin knife meets resistance, continue baking for a few more minutes.
- Let the gratin rest for 10 to 15 minutes before serving.