If you’re looking to elevate your side dish game, this Sweet Potato, Parsnip & Beet Gratin is pure culinary art. It’s as beautiful as it is delicious — layers of jewel-toned vegetables baked in a velvety cream sauce until tender, bubbling, and irresistibly golden on top.
Each bite offers a perfect harmony of flavors: the earthy sweetness of beets, the mild nuttiness of parsnips, and the creamy richness of sweet potatoes. Together, they create a dish that feels both rustic and elegant, hearty yet refined.
This gratin doesn’t just taste good — it looks like a masterpiece. The striking layers make it ideal for special occasions like Thanksgiving, Christmas, or dinner parties, yet it’s simple enough to prepare on an ordinary weeknight when you crave something warm, comforting, and nourishing.
Why You’ll Love This Sweet Potato, Parsnip & Beet Gratin
- A visually stunning dish that impresses every time.
- Creamy, cheesy, and packed with earthy sweetness.
- Perfect for holidays or cozy family dinners.
- Easy to prepare ahead of time and bake before serving.
- Vegetarian-friendly, elegant, and comforting.
Why You Should Try This Recipe
This dish transforms humble root vegetables into something truly special. By baking them in a garlicky cream sauce with Parmesan and thyme, the flavors deepen and meld beautifully. The natural sweetness of the vegetables caramelizes slightly in the oven, while the sauce becomes silky and luxurious.
It’s a side that complements everything from roast chicken to beef tenderloin — or it can stand alone as a hearty vegetarian main course. Each colorful slice looks as good as it tastes, making it a feast for both the eyes and the palate.
Ingredients You’ll Need
- 2 medium sweet potatoes, peeled and thinly sliced
- 2 medium parsnips, peeled and thinly sliced
- 2 medium beets, peeled and thinly sliced
- 2 tablespoons butter
- 2 cloves garlic, minced
- 1 ½ cups heavy cream (or half-and-half for lighter texture)
- 1 teaspoon salt
- ½ teaspoon black pepper
- 1 teaspoon fresh thyme leaves (or ½ teaspoon dried thyme)
- ½ cup grated Parmesan cheese
- ½ cup shredded Gruyère or mozzarella (optional, for extra meltiness)
- Fresh parsley or thyme for garnish
How to Make Sweet Potato, Parsnip & Beet Gratin (Step by Step)
Step 1: Preheat the oven
Preheat to 375°F (190°C) and lightly grease a medium baking dish (about 9×9 inches) with butter or oil.
Step 2: Prepare the vegetables
Peel and thinly slice the sweet potatoes, parsnips, and beets (about ⅛ inch thick). You can use a mandoline slicer for even slices.
Step 3: Make the cream mixture
In a small saucepan, melt butter over medium heat. Add minced garlic and cook for 30 seconds until fragrant. Pour in the cream, salt, pepper, and thyme. Warm through (don’t boil), then remove from heat.
Step 4: Layer the vegetables
Arrange the sliced vegetables in the baking dish, alternating colors for a beautiful pattern (sweet potato, parsnip, beet, repeat). Pour the warm cream mixture evenly over the layers.
Step 5: Add the cheese
Sprinkle Parmesan and Gruyère evenly over the top.
Step 6: Bake until tender
Cover with foil and bake for 40 minutes. Remove the foil and bake another 20 minutes, until the top is golden brown and the vegetables are tender when pierced with a knife.
Step 7: Rest and serve
Let the gratin rest for 10 minutes before slicing. Garnish with fresh parsley or thyme for a pop of color.
Tips for the Best Sweet Potato, Parsnip & Beet Gratin
- Use a mandoline – Even slices ensure uniform cooking.
- Keep layers tight – The closer the slices, the creamier the gratin.
- Warm the cream first – It helps the flavors meld and coats the vegetables evenly.
- Don’t skip the cheese – It adds richness and golden color.
- Cover while baking – Keeps the vegetables tender without burning the top.
- Finish uncovered – Creates that perfect crisp, golden crust.
- Add herbs to the sauce – Thyme, rosemary, or sage pair beautifully.
- Rest before cutting – This helps the layers set and makes slicing easier.
- Add a pinch of nutmeg – For subtle warmth and depth.
- Use gloves for beets – Prevents staining your hands when slicing.
Variations & Substitutions
- Vegan Version: Use coconut cream or cashew cream and vegan cheese.
- Dairy-Free: Substitute plant-based cream and nutritional yeast.
- Cheese Swap: Use cheddar, fontina, or gouda for a richer flavor.
- Add Crunch: Top with breadcrumbs mixed with butter before baking.
- Spicy Twist: Add a pinch of cayenne or smoked paprika.
- Herb Variation: Try rosemary or sage instead of thyme.
- Layer Upgrade: Add thinly sliced onions between the vegetables.
- Nutty Note: Sprinkle chopped walnuts or pecans on top before baking.
- Simplify: Use only sweet potatoes and beets for a quicker version.
- Add Greens: Mix in a handful of chopped kale or spinach.
What to Serve With Sweet Potato, Parsnip & Beet Gratin
- Roasted chicken, pork tenderloin, or steak
- Herb-crusted salmon or roasted cod
- Fresh green salad with balsamic vinaigrette
- Garlic butter rolls or crusty bread
- White wine like Chardonnay or Sauvignon Blanc
- Holiday mains — turkey, ham, or prime rib
Storage & Reheating Tips
To Store:
Refrigerate in an airtight container for up to 3 days.
To Reheat:
Reheat covered in the oven at 350°F (175°C) for 15–20 minutes until warm. Add a splash of cream if the gratin looks dry.
To Freeze:
Freeze before baking (without cheese topping) for up to 1 month. Thaw overnight, add cheese, and bake as directed.
Recipe FAQs
Can I make it ahead of time?
Yes! Assemble it up to a day ahead, refrigerate, then bake just before serving.
Can I use only sweet potatoes?
Of course — it’ll still be delicious, just less colorful.
Can I use pre-cooked beets?
Yes, but reduce the baking time slightly.
Can I skip the cheese?
You can, but the cheese adds depth and richness to the sauce.
Can I use milk instead of cream?
Yes, but the sauce will be thinner — use half milk, half broth for balance.
How do I prevent the beets from bleeding into other layers?
Pat the beet slices dry before layering and alternate with thicker vegetables.
Can I make it vegan?
Yes — use coconut cream and dairy-free cheese.
What if I don’t have parsnips?
Carrots or turnips are great substitutes.
Can I add more protein?
Yes — layer in cooked bacon, ham, or shredded chicken.
How do I make it extra creamy?
Add a little cream cheese or mascarpone to the sauce before pouring.