I love bringing this cheesy root vegetable gratin to Thanksgiving because it turns humble winter vegetables into a creamy, golden side dish. Thin layers of potatoes, carrots, parsnips, and turnips bake in a savory herb cream, with plenty of melted cheese on top.
Why You’ll Love This Cheesy Root Vegetable Gratin
This gratin is hearty enough to feel special, yet simple to prepare with familiar ingredients. The vegetables soften as they bake, while the cream and cheese create a rich sauce and a crisp, browned top. You can assemble it ahead, making it a helpful addition to a busy Thanksgiving menu.
Cheesy Root Vegetable Gratin Ingredients & Substitutions
- 1 pound Yukon Gold potatoes, peeled if desired
- 1 pound carrots, peeled
- 1 pound parsnips, peeled
- 1 pound turnips, peeled
- 2 cups heavy cream
- 1 cup whole milk
- 2 garlic cloves, finely minced
- 1 teaspoon fresh thyme leaves, plus extra for serving
- 1 teaspoon kosher salt
- 1/2 teaspoon black pepper
- 1/8 teaspoon ground nutmeg
- 1 1/2 cups shredded Gruyere cheese, divided
- 1/2 cup finely grated Parmesan cheese
- 1 tablespoon unsalted butter, for greasing the baking dish
For a milder flavor, use sharp white cheddar in place of Gruyere. You can swap in rutabaga for some of the turnip, or use additional potatoes if that is what you have on hand. A mandoline makes even slices, but a sharp knife works well too.
Step-by-Step Instructions to Make Cheesy Root Vegetable Gratin
1. Heat the oven and prepare the dish
Preheat the oven to 375°F (190°C). Butter a 9-by-13-inch baking dish. Peel the vegetables, if desired, and slice them into rounds about 1/8 inch thick so they cook evenly.
2. Make the cream mixture
In a large bowl, whisk together the heavy cream, milk, garlic, thyme, salt, pepper, and nutmeg. Add the sliced vegetables and toss gently to coat.
3. Layer the vegetables
Arrange the vegetable slices in overlapping layers in the prepared dish. Pour the remaining cream mixture over the top, then cover the dish tightly with foil.
4. Bake until tender
Bake for 55 to 65 minutes, until a knife slides easily into the thickest vegetable slices. Carefully remove the foil. If the vegetables are not tender yet, cover and bake for another 10 minutes before adding the cheese.
5. Add cheese and brown the top
Sprinkle the Gruyere and Parmesan evenly over the gratin. Bake uncovered for 15 to 20 minutes, until the top is melted and golden. Let it rest for 10 to 15 minutes before serving so the creamy layers can settle.
Tips for Success
- Slice the vegetables to a similar thickness for even cooking.
- Arrange the slices snugly, but avoid packing them so tightly that the cream cannot move between the layers.
- Cover the dish for the first part of baking to help the vegetables become tender without overbrowning the top.
- Rest the gratin before serving. It will be easier to scoop, and the sauce will cling to the vegetables.
- Oven temperatures can vary, so test the center with a knife before removing the foil.
Variations of Cheesy Root Vegetable Gratin
For a more aromatic version, add a pinch of rosemary or chopped sage to the cream mixture. Swap part of the turnip for thinly sliced rutabaga or sweet potato. To add a little crunch, scatter 1/3 cup of plain breadcrumbs over the cheese during the final 15 minutes of baking.
Serving Suggestions: What to Pair with Cheesy Root Vegetable Gratin
This gratin makes a cozy Thanksgiving side alongside roast turkey, green beans, glazed carrots, or a crisp salad. It also pairs nicely with roasted chicken or a simple lentil main when you want a comforting dinner. Add fresh thyme just before serving for a fragrant finish.
Storage & Reheating Instructions
Cool leftovers, then cover and refrigerate for up to 4 days. Reheat portions in the microwave, or warm the covered baking dish in a 350°F (175°C) oven until heated through. Remove the cover for the final few minutes if you would like to refresh the browned top. For make-ahead prep, assemble the gratin, cover, and refrigerate for up to 1 day. Let it sit at room temperature for about 20 minutes while the oven heats, then bake until the center is tender, adding time as needed.
Memories Made Around the Table
I like setting this gratin near the center of the Thanksgiving table, where everyone can help themselves to a scoop of creamy vegetables and crisp cheese. The warm thyme and garlic make the kitchen smell wonderful while the rest of dinner comes together. It is the kind of side dish that often earns a request for seconds.
FAQs
Can I make cheesy root vegetable gratin ahead of time?
Yes. Assemble it up to 1 day ahead, cover, and refrigerate. Bake it when you are ready to serve, allowing extra time if the dish is still cold from the refrigerator.
How do I know when the vegetables are cooked?
Insert a thin knife into the center of the gratin. The vegetables are ready when the knife slides through easily without much resistance.
Can I use different root vegetables?
Yes. Rutabaga and sweet potato are good options. Keep the total amount close to 4 pounds and slice the vegetables evenly so they cook at a similar rate.
Can I freeze this gratin?
For the best texture, enjoy it fresh or refrigerate leftovers. Cream-based gratins can become grainy after freezing and thawing.
Final Thoughts
This cheesy root vegetable gratin is a comforting, colorful addition to Thanksgiving dinner, with tender layers and a bubbling cheese topping. Prepare it ahead when you can, then let the oven do most of the work while you enjoy the celebration.
Cheesy Root Vegetable Gratin
Equipment
- 1 9-by-13-inch baking dish
- 1 Mandoline (optional)
Ingredients
- 1 pound Yukon Gold potatoes peeled if desired
- 1 pound carrots peeled
- 1 pound parsnips peeled
- 1 pound turnips peeled
- 2 cups heavy cream
- 1 cup whole milk
- 2 cloves garlic finely minced
- 1 teaspoon fresh thyme leaves plus extra for serving
- 1 teaspoon kosher salt
- 0.5 teaspoon black pepper
- 0.125 teaspoon ground nutmeg
- 1.5 cups Gruyere cheese shredded, divided
- 0.5 cup Parmesan cheese finely grated
- 1 tablespoon unsalted butter for greasing the baking dish
Instructions
- Preheat the oven to 375°F (190°C). Butter a 9-by-13-inch baking dish. Peel the vegetables, if desired, and slice them into rounds about 1/8 inch thick so they cook evenly.
- In a large bowl, whisk together the heavy cream, milk, garlic, thyme, salt, pepper, and nutmeg. Add the sliced vegetables and toss gently to coat.
- Arrange the vegetable slices in overlapping layers in the prepared dish. Pour the remaining cream mixture over the top, then cover the dish tightly with foil.
- Bake for 55 to 65 minutes, until a knife slides easily into the thickest vegetable slices. Carefully remove the foil. If the vegetables are not tender yet, cover and bake for another 10 minutes before adding the cheese.
- Sprinkle the Gruyere and Parmesan evenly over the gratin. Bake uncovered for 15 to 20 minutes, until the top is melted and golden. Let it rest for 10 to 15 minutes before serving so the creamy layers can settle.