Root Vegetable Gratin with Sweet Potatoes, Parsnips, and Beets

Introduction

If you’re looking for a side dish that combines rustic comfort with an elegant presentation, this Root Vegetable Gratin with Sweet Potatoes, Parsnips, and Beets is just what you need. Layers of thinly sliced vegetables bake together with a creamy sauce and a touch of cheese, creating a dish that’s both hearty and visually stunning. The mix of earthy beets, naturally sweet parsnips, and velvety sweet potatoes brings a delightful balance of flavors that can elevate any meal.

This gratin isn’t just a feast for your taste buds—it’s also a feast for the eyes. The colorful layers create a mosaic of reds, oranges, and whites, making it perfect for festive occasions or when you want to impress your guests with minimal effort. Whether served as a vegetarian main course or alongside roasted meats, this dish is as versatile as it is delicious.

My recipe story

I first fell in love with gratins during the holidays. While traditional potato gratin was always a crowd favorite, I wanted to create something that felt seasonal, unique, and a bit healthier. Root vegetables seemed like the perfect solution. One chilly autumn evening, I experimented with layering sweet potatoes, parsnips, and beets. The result was a dish that combined creamy richness with earthy sweetness—and the vibrant colors immediately made it a family favorite. Now, it has become a staple at both holiday dinners and cozy weeknight meals.

Every time I prepare this gratin, it reminds me of the joy of experimenting in the kitchen. It’s a dish born out of curiosity, perfected over time, and shared with loved ones who now request it year after year.

Ingredient breakdown

This gratin shines because of the combination of three simple yet distinctive root vegetables. Sweet potatoes bring natural creaminess and a subtle sweetness that balances beautifully with the other flavors. They soften wonderfully in the oven, almost melting into the creamy sauce while holding their structure in layers.

Parsnips, often underrated, contribute a nutty sweetness with a slight hint of spice. They add complexity and pair exceptionally well with dairy, making them a perfect choice for gratins. Finally, beets lend an earthy depth and an incredible ruby-red hue that turns the dish into a work of art. The beets also offer a hint of sweetness that plays nicely with the creamy sauce and cheese topping.

Beyond the vegetables, the creamy sauce ties everything together. Typically made with a blend of milk, cream, garlic, and herbs, it seeps into every layer, ensuring each bite is rich and flavorful. A sprinkle of cheese on top helps form a golden crust that’s both crispy and irresistible.

Equipment you’ll need

• Sharp chef’s knife or mandoline slicer (for thin, even slices)
• Cutting board
• Large mixing bowl
• Measuring cups and spoons
• Oven-safe baking dish (9×13 or similar size)
• Aluminum foil
• Whisk
• Medium saucepan (for the cream sauce)

Step-by-step directions

1. Preheat and prepare the vegetables: Begin by preheating your oven to 375°F (190°C). Peel and thinly slice the sweet potatoes, parsnips, and beets into uniform slices, about 1/8-inch thick. Using a mandoline slicer ensures even thickness, which helps the vegetables cook at the same rate.
2. Make the cream sauce: In a medium saucepan, combine 1 cup heavy cream, 1 cup whole milk, 2 cloves minced garlic, salt, pepper, and a pinch of nutmeg. Heat gently over medium heat until warm and slightly thickened, stirring often. This aromatic sauce will be poured over the vegetable layers to create that luscious gratin texture.
3. Layer the vegetables: Lightly grease your baking dish with butter or oil. Arrange the slices of sweet potatoes, parsnips, and beets in overlapping layers, alternating colors for a beautiful presentation. Continue until all vegetables are used, filling the dish evenly.
4. Pour the sauce and bake: Slowly pour the warm cream sauce over the layered vegetables, making sure it seeps between the slices. Cover the dish with foil and bake for 45 minutes, allowing the vegetables to soften and absorb the flavors of the sauce.
5. Add cheese topping: Remove the foil and sprinkle 1 cup of shredded Gruyère or Parmesan cheese evenly over the top. Return the dish to the oven and bake uncovered for an additional 20–25 minutes, or until the vegetables are tender and the top is golden and bubbling.
6. Cool and serve: Allow the gratin to cool for at least 10 minutes before slicing. This helps the layers set, making it easier to serve neat portions. Garnish with fresh thyme or parsley for an elegant finishing touch.

Variations & substitutions

You can customize this gratin with a variety of flavors and textures. Swap the parsnips for carrots if you prefer a slightly sweeter profile, or use Yukon Gold potatoes for a more traditional gratin base. For a dairy-free option, replace the cream and milk with full-fat coconut milk, which adds a subtle richness while keeping the dish creamy. A sprinkle of goat cheese or feta can also provide tangy contrast to the earthy vegetables. To boost flavor, experiment with herbs like rosemary, sage, or thyme mixed into the cream sauce.

Storage, freezing & make-ahead

This gratin is perfect for preparing ahead. Assemble the dish up to the baking step, cover tightly, and refrigerate for up to 24 hours before baking. Once baked, leftovers can be stored in an airtight container in the refrigerator for 3–4 days. To reheat, cover with foil and warm in a 350°F oven until heated through. For longer storage, freeze the baked gratin in portions for up to 2 months. Thaw overnight in the fridge before reheating in the oven. Keep in mind that while freezing works well, the texture may soften slightly upon reheating.

Serving ideas & pairings

This root vegetable gratin is versatile and pairs beautifully with a wide range of dishes. For a vegetarian spread, serve it with a crisp green salad and roasted Brussels sprouts. If you’re including it in a holiday menu, it pairs wonderfully with roast chicken, turkey, or lamb. A light soup, such as butternut squash or leek and potato, also complements the richness of the gratin. For wine lovers, consider pairing it with a medium-bodied Chardonnay or a light Pinot Noir to balance the earthy sweetness of the vegetables.

FAQ

Can I prepare this gratin without cheese?
Yes! The dish is still delicious without cheese. The creamy sauce provides plenty of richness, and you can top it with breadcrumbs for crunch instead.

How can I make this gratin vegan?
Use coconut milk or almond milk for the sauce and swap the cheese for nutritional yeast or a plant-based cheese alternative.

Do I need to cook the vegetables before layering?
No, thinly slicing them ensures they cook through while baking. Pre-cooking isn’t necessary.

Can I make this with just one type of vegetable?
Absolutely. While the flavor complexity comes from the mix, a single-vegetable gratin with just sweet potatoes or beets will still taste fantastic.

How do I prevent my beets from staining everything?
To minimize bleeding, pat beet slices dry before layering. You can also alternate them with lighter vegetables to keep colors more defined.

Final thoughts

This Root Vegetable Gratin with Sweet Potatoes, Parsnips, and Beets is more than just a side dish—it’s a celebration of seasonal produce and comforting flavors. Its vibrant appearance makes it table-worthy for holidays and gatherings, while its rich, creamy layers ensure every bite is deeply satisfying. Whether you’re introducing it as a new holiday tradition or enjoying it on a cozy evening at home, this gratin is sure to impress and delight.

So, gather your root vegetables, preheat your oven, and prepare to create a dish that’s as beautiful as it is delicious. Once you try it, you’ll want to make it part of your seasonal cooking rotation year after year.

Root Vegetable Gratin with Sweet Potatoes, Parsnips, and Beets

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• Author: Sarah White
• Total Time: 1 hour 35 minutes
• Yield: 6 servings 1x
• Diet: Vegetarian

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Description

A colorful, creamy gratin layered with sweet potatoes, parsnips, and beets. Perfect as a festive side or a comforting vegetarian main dish.

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Ingredients

Scale 1x2x3x

• 2 medium sweet potatoes, peeled and thinly sliced

• 2 medium parsnips, peeled and thinly sliced

• 2 medium beets, peeled and thinly sliced

• 1 cup heavy cream

• 1 cup whole milk

• 2 cloves garlic, minced

• 1/2 tsp salt

• 1/4 tsp black pepper

• Pinch of nutmeg

• 1 cup shredded Gruyère or Parmesan cheese

• 1 tbsp butter or oil for greasing

• Fresh thyme or parsley for garnish

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Instructions

1. Preheat oven to 375°F (190°C) and grease a 9×13-inch baking dish.
2. Thinly slice sweet potatoes, parsnips, and beets into even rounds.

3. In a saucepan, warm cream, milk, garlic, salt, pepper, and nutmeg until slightly thickened.

4. Arrange vegetable slices in overlapping layers in the baking dish, alternating colors.
5. Pour warm cream mixture evenly over the vegetables. Cover with foil and bake 45 minutes.

6. Remove foil, sprinkle cheese over the top, and bake uncovered for 20–25 minutes until golden.

7. Let rest 10 minutes before serving. Garnish with fresh herbs.

Notes

 For a lighter option, use half-and-half instead of cream. Can be assembled a day ahead and refrigerated before baking. Leftovers keep 3–4 days refrigerated or up to 2 months frozen.

• Prep Time: 25 minutes
• Cook Time: 1 hour 10 minutes
• Category: Side Dish
• Method: Baking
• Cuisine: European