Root Vegetable Gratin with Sweet Potatoes, Parsnips, and Beets

If you’re looking for a side dish that’s as beautiful as it is delicious, this Root Vegetable Gratin with Sweet Potatoes, Parsnips, and Beets is a showstopper. Layered in vibrant slices and smothered in a garlicky herb cream, this gratin is rich, earthy, and comforting in the most satisfying way. It’s the kind of recipe that earns a spot at your holiday table and your weeknight dinner rotation.

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What Is Root Vegetable Gratin?

Root Vegetable Gratin is a creamy, baked casserole made with layers of thinly sliced root vegetables—in this case, sweet potatoes, parsnips, and beets—smothered in a seasoned cream sauce and baked until tender, bubbling, and golden.

It’s a twist on classic potato gratin, but with more depth of flavor, natural sweetness, and color. The beets lend a gorgeous pink hue, the sweet potatoes bring richness, and the parsnips offer a nutty sharpness that cuts beautifully through the cream.

Why You’ll Love This Root Vegetable Gratin

• Gorgeous layers and colors—truly table centerpiece worthy
• Naturally gluten-free and vegetarian
• Perfect balance of earthy, creamy, and savory
• Works as a holiday dish or a cozy weeknight side
• Make-ahead friendly and reheats like a dream

What Does It Taste Like?

It’s creamy and indulgent without being too heavy. The sweet potatoes and beets add a natural sweetness, while the parsnips give it an earthy, peppery bite. The cream sauce, infused with garlic and herbs, soaks into every layer and creates that irresistible, golden-browned top. Every bite has contrast—soft and crispy, sweet and savory, rich and fresh.

Benefits of This Recipe

• Packed with fiber, antioxidants, and vitamins
• A great way to use up seasonal produce
• Impressive enough for guests, easy enough for a weeknight
• Easy to scale up for a crowd
• Freezer and make-ahead friendly

Ingredients for Root Vegetable Gratin

• 2 medium sweet potatoes, peeled and thinly sliced
• 2 medium parsnips, peeled and thinly sliced
• 2 medium beets, peeled and thinly sliced
• 1 ½ cups heavy cream (or a mix of cream and whole milk)
• 2 cloves garlic, minced
• 1 tablespoon fresh thyme (or 1 tsp dried)
• ½ teaspoon salt
• ¼ teaspoon black pepper
• ½ cup grated Parmesan cheese
• Optional: ¼ teaspoon nutmeg for warmth
• Optional topping: extra Parmesan or Gruyère cheese for baking

Pro tip: A mandoline slicer is super helpful here for uniform slices and even cooking.

Tools You’ll Need

• Mandoline or sharp knife
• Large mixing bowl
• Casserole or baking dish (8×8 or similar)
• Whisk
• Aluminum foil
• Oven

Ingredient Additions & Substitutions

• Add onions: Thin slices of red onion or shallot layered in bring extra savoriness.
• Make it vegan: Use full-fat coconut milk or a plant-based cream alternative and skip the cheese or sub in a vegan version.
• Add herbs: Rosemary or sage pair beautifully with the earthy roots.
• Use different roots: Try rutabaga, carrots, or turnips in place of or alongside the others.
• Make it cheesy: Add shredded Gruyère or white cheddar between layers for a more decadent version.

How to Make Root Vegetable Gratin with Sweet Potatoes, Parsnips, and Beets

1. Preheat your oven to 375°F (190°C). Lightly grease your baking dish.
2. Make the cream mixture: In a small bowl, whisk together the cream, garlic, thyme, salt, pepper, and nutmeg (if using).
3. Slice the vegetables: Use a mandoline or sharp knife to thinly slice the sweet potatoes, parsnips, and beets—about 1/8 inch thick.
4. Layer the veggies: In your baking dish, alternate layers of sweet potatoes, parsnips, and beets in a pattern or spiral for a stunning visual. Pour some of the cream mixture over each layer as you go.
5. Finish with cheese: Once all vegetables are layered and cream is poured in, top with Parmesan cheese.
6. Bake covered: Cover with foil and bake for 35 minutes.
7. Uncover and finish: Remove foil, add additional cheese on top if desired, and bake another 20–25 minutes until golden, bubbly, and vegetables are tender.
8. Rest before serving: Let sit for 10 minutes before slicing so the sauce sets slightly.

What to Serve with Root Vegetable Gratin

This gratin pairs beautifully with:

• Roast chicken or turkey
• Grilled sausages or pork tenderloin
• A crisp arugula salad with lemon vinaigrette
• Green beans or Brussels sprouts for added freshness
• A glass of dry white wine like Chardonnay or Sauvignon Blanc

Tips for the Best Root Vegetable Gratin

• Uniform slices help everything cook evenly—don’t rush the prep!
• Let the gratin rest before slicing—this helps the cream thicken and settle.
• Taste your cream mixture before adding—adjust salt or herbs to preference.
• Use heavy cream or full-fat milk for the best texture.
• For extra crispy top, broil for 1–2 minutes at the end (watch closely!).

Storage Instructions

• Fridge: Store leftovers in an airtight container for up to 4 days.
• Freezer: Freeze fully baked gratin slices individually. Reheat in oven or toaster oven.
• Reheat: Bake at 350°F until warmed through, or microwave gently.

Frequently Asked Questions

Can I make this ahead of time?

Yes! Assemble and refrigerate (unbaked) up to 1 day in advance. Bake just before serving.

Can I use pre-cooked or roasted veggies?

You can, but reduce the baking time and be aware the texture may be softer.

Is it okay if my beets stain the other veggies?

Totally normal! Beets will bleed slightly into the cream and other layers. If you want cleaner color separation, roast or steam the beet slices separately before layering.

Can I make it dairy-free?

Yes. Use a full-fat plant-based milk (like oat or coconut cream) and skip or sub the cheese.

Conclusion

This Root Vegetable Gratin with Sweet Potatoes, Parsnips, and Beets is the kind of recipe that stops people mid-bite—not just because it’s gorgeous, but because it’s bursting with seasonal flavor and rich, creamy comfort. Whether you serve it for the holidays or just a cozy fall dinner, this dish brings the wow factor every time.

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