If you’re looking to wow your guests this season with a dish that’s both comforting and elegant, you’re going to adore my Cheesy Root Vegetable Gratin Recipe. This cozy, creamy gratin bursts with the natural sweetness of sweet potatoes, earthy beets, and gently spiced parsnips, all wrapped in a luscious cheese and thyme sauce. I first tried this during a chilly fall gathering, and every bite just felt like a warm hug. Stick with me here—I promise you’ll want to bookmark this one for every festive dinner!

❤️

Why You’ll Love This Recipe

Lush and Creamy Texture: The mix of heavy cream and cheeses creates a velvety sauce that clings perfectly to the root veggies.
Vibrant and Seasonal: This gratin shines thanks to the sweet, earthy flavors of fresh root vegetables you can find any fall or winter.
Easy to Prepare: Slicing thinly and layering in the dish is straightforward, especially with a mandoline—making it beginner-friendly.
Perfect Make-Ahead Dish: Prep up to a day in advance to ease your holiday stress without compromising taste or texture.

An oval metal baking dish holds a colorful layered vegetable gratin arranged in a neat row of five groups. Starting from the top left, there is a layer of bright orange slices, followed by a layer of pale yellow slices with light browning, next to a middle layer of deep purple slices with some charred edges. Below that, there is another layer of bright orange slices, similar to the top, and lastly, a layer of pale off-white slices with some golden spots at the bottom right. The slices are thin and arranged closely in vertical rows, with some fresh green herb sprigs sprinkled on top. A large metal spoon rests inside the dish on a white marbled surface beneath it. photo taken with an iphone --ar 2:3 --v 7 - Cheesy Root Vegetable Gratin, root vegetable gratin, cheesy vegetable casserole, fall vegetable side dish, comfort food with root vegetables

Ingredients You’ll Need

Putting together this Cheesy Root Vegetable Gratin Recipe calls for ingredients that balance each other beautifully, bringing earthy sweetness together with rich creaminess. Choosing fresh, high-quality veggies and good cheese really makes a difference here.

Flat lay of a small pat of unsalted butter, a long whole peeled sweet potato sliced in thin rounds, large peeled parsnips sliced in thin rounds, small peeled beets sliced in thin rounds, a small white bowl filled with heavy cream, a small white bowl of grated Parmesan cheese, a small white bowl of fresh minced thyme, a single garlic clove, a small white bowl with shredded Gruyere cheese, salt and pepper scattered naturally around, placed on a clean white marble surface, soft natural light, photo taken with an iPhone, professional food photography style, fresh ingredients, white ceramic bowls, no bottles, no duplicates, no utensils, no packaging --ar 2:3 --v 7 --p m7354615311229779997 - Cheesy Root Vegetable Gratin, root vegetable gratin, cheesy vegetable casserole, fall vegetable side dish, comfort food with root vegetables

Unsalted butter: For greasing your dish so the gratin doesn’t stick and gets that lovely crust on the edges.
Long sweet potatoes: Their natural sweetness contrasts perfectly with the tangy cheeses; peel them for best texture.
Parsnips: Earthy and slightly nutty; trimming them well ensures no bitterness in the final dish.
Small beets: These add a beautiful pop of color and deep flavor, just be mindful about their staining properties!
Heavy cream: The key for that rich binding sauce; whole milk can be used but won’t be as luscious.
Parmesan cheese: Adds sharp, salty flavor and a fantastic crust when baked.
Fresh thyme: Aromatic and woody, bringing the whole dish together with herbal brightness.
Garlic clove: Minced for a subtle savory kick that’s not overpowering.
Shredded Gruyere: Melts beautifully and adds a nutty, gooey finish on top.
Salt and pepper: Simple seasonings that elevate every ingredient’s natural flavor.

📝

Note: You’ll find the complete list of ingredients, along with their exact measurements, in the printable recipe card at the bottom of this post.

Variations

I love customizing this Cheesy Root Vegetable Gratin Recipe depending on the occasion and what’s in season. Feel free to experiment—you’ll find that tweaking it slightly can keep it fresh every time you make it.

Vegetable swap: I personally like to swap out beets for sweet golden beets or even add thinly sliced turnips for a peppery bite.
Cheese alternative: If you want a sharper bite, try adding a bit of shredded sharp cheddar or swapping Gruyere with fontina.
Dairy-free option: Use coconut cream or cashew cream as an alternative and choose a vegan cheese to top it off.
Herb twists: Rosemary or sage work beautifully if you want to switch things up from thyme.

How to Make Cheesy Root Vegetable Gratin Recipe

Step 1: Prep Your Veggies Like a Pro

First things first, preheat your oven to 400˚F and butter your baking dish generously—this helps the edges crisp up nicely. Then, slice your sweet potatoes, parsnips, and beets into very thin rounds, ideally with a mandoline if you have one (it’s a game changer for speed and uniformity). Keeping each veggie in separate bowls makes seasoning much simpler and prevents the flavors from mixing prematurely.

Step 2: Cream, Cheese, and Thyme Magic

Next, pour 4 tablespoons of cream over the sweet potatoes and parsnips, and 2 tablespoons over the beets—trust me, that little difference keeps the beets from overpowering the dish in color and flavor. Toss each bowl with half an ounce of grated Parmesan, a teaspoon of fresh minced thyme, and plenty of salt and pepper. This is where the layers start building flavor, so don’t skimp on the seasoning.

Step 3: Layer It Up and Bake

Pour the remaining 1/4 cup of cream into the bottom of your buttered dish, then sprinkle with the last half-ounce of Parmesan and the minced garlic for an aromatic base. Now for the fun part: line up the sweet potato slices standing on a slight bias at one end, then the parsnips, then beets, and repeat until you have six beautiful rows. Season the top with salt, pepper, and leftover Parmesan, then cover with foil and pop it in the oven for 30 minutes. This covered bake lets the veggies soften gently.

Step 4: Cheese It and Finish Baking

After 30 minutes, uncover and sprinkle the top with shredded Gruyere. Return it to the oven uncovered for another 18 to 20 minutes until the top is golden and bubbly, and the vegetables are tender when poked with a fork. I love that crispy cheesy crust—it’s what really brings the dish home.

Once out of the oven, sprinkle fresh thyme leaves on top for that fresh herbal pop and serve it warm. Trust me when I say this gratin practically disappears off the table!

👨‍🍳

Pro Tips for Making Cheesy Root Vegetable Gratin Recipe

Mandoline Use: Using a mandoline for slicing helps ensure uniform thickness, which means even cooking and a pleasing baked texture.
Managing Beet Color: Coat beets lightly with cream to avoid bleeding that can tint your whole gratin an unexpected shade but still tastes amazing.
Layering Technique: Standing slices on a slight bias creates a stunning presentation and helps veggies cook evenly through the layers.
Covering During Baking: Start covered so veggies steam and become tender; uncover at the end to crisp the cheese topping perfectly.

How to Serve Cheesy Root Vegetable Gratin Recipe

Cheesy Root Vegetable Gratin Recipe - Serving

Garnishes

Fresh thyme leaves are my go-to finishing touch because they add lovely color and brighten the rich, cheesy flavors without overwhelming the roots. A light sprinkle of freshly cracked black pepper right before serving also adds a subtle kick that lifts each mouthful.

Side Dishes

I often pair this gratin with roasted turkey or chicken for a hearty holiday plate, along with a crisp green salad or sautéed green beans to balance all that richness. It also goes surprisingly well with a simple vinaigrette-dressed side of roasted Brussels sprouts.

Creative Ways to Present

For special occasions, I like to prepare this gratin in individual ramekins—it feels a bit more fancy and makes portion control easier. Not to mention, a sprinkle of finely chopped toasted walnuts on top can add a delightful crunch that surprises guests without detracting from the creamy foundation.

Make Ahead and Storage

Storing Leftovers

I store any leftovers tightly covered in the fridge for up to 3 days. The flavors actually deepen overnight, which I love, but the texture of the gratin can soften, so reheating carefully is important to keep the veggies from turning mushy.

Freezing

I’ve frozen this gratin successfully, but I recommend freezing before adding the Gruyere topping. Wrap the gratin tightly and freeze for up to 2 months. Thaw overnight in the fridge before baking, and add the shredded cheese just prior to finishing the bake for the best melt and browning.

Reheating

To reheat, I cover the gratin loosely with foil and bake at 350˚F until warmed through, about 20 minutes. To revive the crispy top, remove the foil in the last 5 minutes of baking. This way, you keep that fresh-from-the-oven appeal even with leftovers.

FAQs

Can I make the Cheesy Root Vegetable Gratin Recipe vegan or dairy-free?

Yes! Swap out the heavy cream for full-fat coconut cream or cashew cream, and use a plant-based cheese alternative instead of Parmesan and Gruyere. Fresh herbs and garlic will still elevate the dish nicely.
What’s the best way to slice the root vegetables evenly?

Using a mandoline slicer is the easiest and safest way to get uniform, thin rounds which ensures even cooking and that classic gratin texture. If you don’t have one, a very sharp knife and patience will do—just try to keep slices as thin as possible and consistent.
Can I prepare this gratin ahead of time?

Absolutely! You can assemble the gratin up to one day ahead, cover tightly with foil, and refrigerate. When you’re ready to bake it, just add a few extra minutes to the covered baking time. Just be aware the beets may bleed slightly in the cream but that won’t affect the flavor.
Is it okay to substitute whole milk for heavy cream?

You can, but the gratin won’t be quite as rich or creamy, and the sauce may not thicken as nicely. I recommend heavy cream for the best results, but whole milk works in a pinch.

Final Thoughts

I genuinely love how this Cheesy Root Vegetable Gratin Recipe brings together simple ingredients into something that feels special and indulgent without fuss. It’s become my family’s favorite during the holidays, and watching everyone dig in with second and third helpings never gets old. If you’re looking for a dish that’s both beautiful and bursting with flavor, give this one a try—you’ll impress your guests, and trust me, you’ll want to make it again and again.