Description
This Cheesy Root Vegetable Gratin is a delightful and comforting dish featuring thinly sliced sweet potatoes, parsnips, and beets baked in a creamy Parmesan and Gruyere cheese mixture. Infused with fresh thyme and garlic, this gratin offers a perfect balance of rich flavors and tender textures, ideal as a hearty side or vegetarian main course.
Ingredients
Scale
Vegetables
- 1-2 long sweet potatoes (about 2 inches thick), peeled
- 3-4 large parsnips, ends trimmed and peeled
- 3-5 small beets, peeled
Dairy & Cheese
- 14 tablespoons heavy cream, divided (whole milk can be used for a lighter dish)
- 4 ounces grated Parmesan, divided
- 1 ounce shredded Gruyere
- 1 tablespoon unsalted butter, softened (for greasing dish)
Herbs & Seasonings
- 1 tablespoon fresh minced thyme, divided (+ extra for garnish)
- 1 garlic clove, minced
- Salt and pepper to taste
Instructions
- Preheat and prepare dish: Preheat your oven to 400°F (200°C). Grease a 3-quart baking dish with softened butter and set it aside to prevent sticking and ensure even baking.
- Slice the vegetables: Using a mandoline slicer, slice the sweet potatoes, parsnips, and beets into very thin, even rounds. Place each type of vegetable into its own separate bowl to keep flavors distinct for seasoning.
- Mix vegetables with cream and cheese: Add 4 tablespoons of heavy cream to the bowls with sweet potatoes and parsnips, and 2 tablespoons to the beet bowl. Then mix in ½ ounce of grated Parmesan, 1 teaspoon of minced thyme, salt, and pepper into each. Toss gently to coat the slices evenly with the creamy mixture.
- Prepare the baking dish layering: Pour the remaining ¼ cup of heavy cream into the greased baking dish. Sprinkle half an ounce of Parmesan and the minced garlic over the cream. Arrange the vegetable slices in rows inside the dish in this order: sweet potato, parsnip, beet, and repeat until all slices are used, layering them evenly.
- Season and start baking: Sprinkle the top layer of vegetables with the remaining Parmesan, salt, and pepper. Cover the dish tightly with foil to keep moisture in and bake for 30 minutes, allowing the vegetables to begin softening.
- Add Gruyere and finish baking: Remove the foil and sprinkle the shredded Gruyere cheese evenly over the top. Return the dish to the oven uncovered and bake for an additional 18-20 minutes until the vegetables are tender and the cheese topping is golden and bubbly.
- Garnish and serve: Once baked, garnish the gratin with fresh thyme leaves. Serve warm as a comforting side dish or a satisfying vegetarian entrée.
Notes
- For a lighter version, substitute whole milk for heavy cream though the gratin will be less rich.
- Using a mandoline is recommended for uniformly thin slices ensuring even cooking, but a sharp knife can be used carefully instead.
- Covering with foil during the initial baking locks in moisture, preventing the vegetables from drying out.
- This dish pairs well with roasted meats or can be served as a hearty vegetarian main accompanied by a crisp green salad.
- Leftovers can be refrigerated for up to 3 days and reheated covered in the oven for best texture.
