This Cheesy Root Vegetable Gratin is as stunning as it is delicious. Layers of sweet potatoes, parsnips, and beets are baked with cream, garlic, and gruyère cheese to create a cozy and elegant side dish—perfect for Thanksgiving, Christmas, or any special occasion.
Ingredients
- 1 tablespoon unsalted butter, softened
- 1–2 long sweet potatoes (about 2 inches thick), peeled
- 3–4 large parsnips, peeled and trimmed
- 3–5 small beets, peeled
- 14 tablespoons heavy cream, divided (or whole milk)
- 4 ounces grated Parmesan, divided
- 1 tablespoon fresh minced thyme, divided, plus more for garnish
- 1 garlic clove, minced
- 1 ounce shredded gruyère
- Salt and pepper, to taste
Instructions
- Prep the Oven and Dish
Preheat oven to 400˚F. Grease a 3-quart (oval) baking dish with butter. - Slice the Vegetables
Slice sweet potatoes, parsnips, and beets into very thin rounds (a mandoline works best). Transfer each vegetable to its own bowl. - Season the Vegetables
Pour 4 tablespoons of cream over the sweet potatoes and parsnips, and 2 tablespoons over the beets. Add ½ ounce Parmesan and 1 teaspoon thyme to each bowl. Season generously with salt and pepper and toss until coated. - Prepare the Baking Dish
Pour the remaining ¼ cup cream into the bottom of the prepared dish. Sprinkle with ½ ounce Parmesan and minced garlic. - Arrange the Vegetables
Stand the vegetables on a slight diagonal in the dish in layers: sweet potatoes first, then parsnips, followed by beets. Repeat until all vegetables are arranged, creating six vertical rows. Season the top with salt, pepper, and the remaining Parmesan. - Bake Covered
Cover with foil and bake for 30 minutes or until the vegetables are tender. - Add Cheese and Finish Baking
Remove foil, sprinkle shredded gruyère on top, and bake uncovered for an additional 18–20 minutes until the vegetables are fork-tender and the top is lightly browned. - Garnish and Serve
Finish with fresh thyme leaves and serve warm.
Tips
- Beets Bleeding: Coat beet slices lightly in cream to prevent their color from spreading too much.
- Mandoline: Ensures even slices for uniform cooking and saves prep time.
- Make Ahead: Assemble up to a day ahead and refrigerate tightly covered. Add 5–7 extra minutes to baking time when ready to cook.
- Cheese Variations: Fontina, Swiss, Gouda, or mild cheddar work well instead of gruyère.
- Vegetable Alternatives: Turnips or rutabaga can replace any of the root vegetables.
Prep Time: 15 minutes | Cook Time: 50 minutes | Total Time: 1 hour 5 minutes | Servings: 8