Name: Cheesy Root Vegetable Gratin Recipe
Prep time: 15 min
Cook time: 50 min
Total time: 1 h 5 min
Cuisine: American
Ingredients: 2 long sweet potatoes (about 2 inches thick), peeled; 4 large parsnips, ends trimmed and peeled; 5 small beets, peeled; 1 tablespoon unsalted butter softened; 14 tablespoons heavy cream, divided; 4 ounces grated Parmesan, divided; 1 ounce shredded Gruyere cheese; 1 tablespoon fresh minced thyme, divided plus more for garnish; 1 garlic clove, minced; Salt and pepper to taste

Jump to Recipe·5 from 27 reviews

If you’re craving a comforting dish that feels like a warm hug on a chilly evening, you’re going to adore this Cheesy Root Vegetable Gratin Recipe. Root veggies like sweet potatoes, parsnips, and beets get transformed into tender, cheesy slices baked to golden perfection. Trust me, once you taste it, this gratin will quickly become your go-to side for cozy dinners or holiday gatherings. Stick with me—I’ll walk you through every step to make this fan-freaking-tastic recipe a breeze in your kitchen!

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Why This Recipe Works

Perfect Veggie Trio: Sweet potatoes, parsnips, and beets each bring unique sweetness and earthiness that balance beautifully.
Cream & Cheese Harmony: The creamy base thickens nicely and the combo of Parm and Gruyere creates rich, melty goodness.
Layered Texture: Thinly sliced veggies bake evenly and stand upright for an impressive presentation that’s surprisingly easy.
Simple Seasoning: Fresh thyme and garlic add fragrant depth without overwhelming the natural flavors.

Cheesy Root Vegetable Gratin, root vegetable gratin, cheesy vegetable bake, holiday side dish, comforting vegetable casserole - This dish shows an oval white metal pan with five rows of thinly sliced vegetables arranged standing up in neat, overlapping layers. Starting from the top, the first row is dark orange sweet potatoes with a slightly crispy browned edge. The second row has pale yellow sliced potatoes with a light golden crust and some green herbs on top. The third row consists of deep purple slices, possibly beets, with a shiny, roasted look and a few sprinkle of herbs. The fourth row repeats the bright orange sweet potatoes with a rich roasted color and some herbs scattered on top. The last row at the bottom shows pale yellow potatoes again with gentle browning and fresh herbs. The pan is on a white marbled surface with a beige cloth and a silver spoon to the right. Photo taken with an iphone --ar 2:3 --v 7

Ingredients & Why They Work

The ingredients in this Cheesy Root Vegetable Gratin Recipe come together for both flavor and texture. Each veggie has a distinct personality that makes the dish feel layered and special. Pick fresh, firm veggies and good quality cheese for the best results.

Cheesy Root Vegetable Gratin, root vegetable gratin, cheesy vegetable bake, holiday side dish, comforting vegetable casserole - Flat lay of a few long peeled sweet potatoes sliced into thin rounds in a simple white ceramic bowl, several peeled parsnips cut into thin rounds in another white ceramic bowl, a handful of peeled small beets sliced into thin rounds in a third white ceramic bowl, a small white ceramic bowl filled with heavy cream, a small white ceramic bowl with grated Parmesan cheese, a small white ceramic bowl holding shredded Gruyere cheese, a fresh small bunch of thyme sprigs, one garlic clove unpeeled, a small pat of unsalted butter, whole uncracked brown eggs, all arranged in perfect symmetrical balance, 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

Sweet potatoes: Their gentle sweetness softens to creamy perfection, pairing beautifully with savory cheese.
Parsnips: They add a subtle nutty flavor and a bit of a bite, balancing the sweetness.
Beets: Earthy and colorful, beets bring visual beauty and a rich, deep flavor.
Heavy cream: It’s essential for that luscious, velvety sauce that binds everything.
Parmesan cheese: Grated fresh, it lends sharp, salty notes and helps thicken the cream.
Gruyere cheese: Melts beautifully on top with a nutty, buttery flavor.
Fresh thyme: Adds woodsy herbal brightness that cuts through the richness.
Garlic: Gives just enough kick and aroma without overpowering.
Unsalted butter: Used for greasing the dish, preventing sticking and adding subtle richness.
Salt and pepper: To taste, but don’t skimp—they’re crucial for elevating every layer of flavor.

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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.

Tweak to Your Taste

One of my favorite things about this Cheesy Root Vegetable Gratin Recipe is how easy it is to make it your own. Whether you want a dairy-free version or prefer a different herb, you can adjust it without losing that cozy, cheesy magic.

Variation: I’ve swapped fresh rosemary or sage for thyme when I wanted a slightly earthier, more piney aroma — totally delicious and just as comforting.
Dietary modification: For a lighter take, try using half-and-half instead of heavy cream, or a plant-based cream if you’re dairy-free. Just expect a slightly less thick sauce.
Seasonal swaps: Don’t have beets? Try thinly sliced turnips or rutabagas instead—they hold up well and add that root veggie charm.

Step-by-Step: How I Make Cheesy Root Vegetable Gratin Recipe

Step 1: Prep Your Oven and Dish

First things first, preheat your oven to 400˚F. Then, grab a 3-quart baking dish and give it a thorough greasing with softened unsalted butter. The butter not only prevents sticking but adds a subtle richness that complements the creamy layers ahead. This simple step sets you up perfectly for a gratin that slides right out when it’s done.

Step 2: Slice Your Veggies Thin

Next, peel and slice your sweet potatoes, parsnips, and beets into very thin rounds. If you have a mandoline, now’s the time to use it—it saves a ton of time and keeps the slices uniform, so everything cooks evenly. I like to keep each vegetable separate in their own bowls; it makes seasoning easier and helps the flavors soak in nicely.

Step 3: Season & Coat the Vegetables

Pour 4 tablespoons of heavy cream over the sweet potatoes and parsnips, and 2 tablespoons over the beets since they release so much moisture. Then toss each bowl with ½ ounce of grated Parmesan and 1 teaspoon of minced thyme. Don’t forget to season with plenty of salt and pepper here—this is where your veggies start building their flavor foundation. Toss everything gently but thoroughly, making sure every slice is lovingly coated in that cheesy, creamy mix.

Step 4: Build the Base & Layer Your Gratin

Pour the remaining ¼ cup of cream into the bottom of your buttered baking dish, then sprinkle ½ ounce of Parmesan and the minced garlic over it. This flavorful base keeps the veggies from sticking and infuses the whole gratin with garlicky goodness. Now, stand your sweet potatoes upright on a bias, lining one side of the dish. Next, layer rows of parsnips, then beets. Repeat the pattern to fill the dish with six rows total. This vertical stacking isn’t just pretty—it ensures the edges crisp up beautifully while the insides stay tender.

Step 5: Season the Top and Bake Covered

Finish by seasoning the top with salt, pepper, and the remaining Parmesan. Cover the gratin tightly with foil and pop it into the oven for 30 minutes. You want the vegetables to become soft and tender, but still hold their shape. Covering also helps the cream thicken and soak into those slices without drying out.

Step 6: Add Gruyere & Finish Baking

Remove the foil and sprinkle shredded Gruyere evenly on top. This cheese melts into a nutty, golden crust you’re going to love. Return the dish to the oven, uncovered, and bake for another 18 to 20 minutes. You’re looking for a bubbly, lightly browned top and fork-tender veggies underneath. The aroma alone will have you reaching for a plate before it even cools!

Step 7: Garnish & Serve

Once out of the oven, sprinkle fresh thyme leaves over the top for a final burst of fragrance and color. Let your gratin rest a few minutes before serving so it sets up nicely. This dish shines on its own but also stars as a stellar side at your dinner table.

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Pro Tips for Making Cheesy Root Vegetable Gratin Recipe

Use a Mandoline: It’s the easiest way to get perfectly thin, even slices that bake evenly. Plus, it saves chopping time.
Don’t Overcrowd Your Dish: Standing the slices on their sides helps, but if your dish is too small, veggies might steam instead of roasting crisp.
Handle Beets with Care: They can bleed color into the cream if prepped ahead. I prefer to slice and assemble right before baking to avoid this.
Rest Before Serving: Let the gratin cool a bit after baking so it firms up and cuts cleanly—makes serving much easier!

How to Serve Cheesy Root Vegetable Gratin Recipe

Cheesy Root Vegetable Gratin, root vegetable gratin, cheesy vegetable bake, holiday side dish, comforting vegetable casserole - A metal baking dish holds a layered vegetable gratin with five distinct rows of thinly sliced rounds arranged in a slightly curved pattern. The layers alternate in colors: dark purple eggplant on the far left, light yellow potato next to it, deep red beetroot in the center, bright orange sweet potato to the right, and creamy off-white potato on the far right. Each vegetable slice shows slight browning and charring at the edges, with a few fresh green thyme leaves sprinkled on top. A silver spoon rests inside the dish at the bottom left, partially covered with sauce residue. The background is a white marbled texture. Photo taken with an iphone --ar 2:3 --v 7

Garnishes

I love finishing this gratin with fresh thyme sprigs or a light sprinkle of chopped parsley for a pop of green and fresh aroma. Sometimes, I add a drizzle of good olive oil right before serving for a silky touch. It’s little things like that which elevate this dish from tasty to memorable.

Side Dishes

This gratin is a wonderful partner for roasted meats like chicken or pork, and is equally at home beside pan-seared salmon. I often serve it alongside a crisp green salad to balance the richness. For a vegetarian feast, pair it with lentil stew or sautéed leafy greens for a complete meal.

Creative Ways to Present

For a special occasion, try assembling individual mini gratins in ramekins for that wow factor. You can play with patterns—maybe alternating rows of beets and parsnips for a colorful swirl effect. Another fun idea: sprinkle toasted nuts like hazelnuts on top at the end for added crunch and flavor contrast.

Make Ahead and Storage

Storing Leftovers

I usually store leftover gratin in an airtight container or cover the baking dish tightly with foil and refrigerate. It holds up well for 3-4 days, making it a fantastic make-ahead dish for busy weeks.

Freezing

Freezing works too, but I recommend portioning the gratin into smaller containers before freezing for easier reheating. Just thaw overnight in the fridge, then reheat in the oven to bring back that melty texture—though the crispy top may soften a bit.

Reheating

To reheat, I pop leftovers in a 350˚F oven covered with foil for about 15 minutes until warmed through, then remove the foil for 5 more minutes to crisp the top a touch. Avoid microwaving if you want to keep the texture nice and creamy without sogginess.

FAQs

Can I use other root vegetables in this Cheesy Root Vegetable Gratin Recipe?

Absolutely! While sweet potatoes, parsnips, and beets are classic for this gratin, you can substitute or add turnips, rutabagas, or even carrots. Just slice them thinly so they cook evenly. Keep in mind different vegetables might change cooking time slightly.
What cheese works best for the top layer?

Gruyere is my top pick for its meltability and nutty flavor, but you can also use fontina, mozzarella, or even cheddar depending on your taste. Just choose a cheese that melts smoothly without getting too oily.
How do I prevent beets from bleeding into the cream?

To minimize beet bleeding, slice them just before assembling and coat them lightly in cream rather than soaking. Also, coating the baking dish base with cream and Parmesan helps create a barrier that reduces color leaching. While the color might still tint the cream a bit, it won’t affect the flavor.
Can I make this Cheesy Root Vegetable Gratin Recipe ahead of time?

You can prep and assemble the gratin up to a day ahead—just make sure to cover it tightly and refrigerate. When ready, bake covered for a bit longer (about 5–7 minutes extra) to ensure veggies cook through. Just be aware beets might bleed a little during refrigeration.

Final Thoughts

This Cheesy Root Vegetable Gratin Recipe is one of those dishes I keep coming back to because it’s both simple and elegant. It turns humble root vegetables into a comforting, crowd-pleasing experience with every bite. Whether you’re serving a special holiday meal or just want a cozy side for weeknight dinner, this recipe offers reliable success and plenty of room for your personal flair. I hope you enjoy making—and devouring—it as much as I do! Happy cooking, friend.