Description
This Cheesy Root Vegetable Gratin is a comforting and elegant side dish featuring thinly sliced sweet potatoes, parsnips, and beets layered in a creamy, cheesy sauce with fresh thyme and garlic. Baked to golden perfection, this gratin offers a rich blend of textures and flavors perfect for any occasion.
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 & Seasonings
- 1 tablespoon unsalted butter, softened
- 14 tablespoons heavy cream, divided (whole milk can be used but will be less creamy)
- 4 ounces grated Parmesan cheese, divided
- 1 ounce shredded Gruyere cheese
- 1 tablespoon fresh minced thyme, divided plus more for garnish
- 1 garlic clove, minced
- Salt and pepper, to taste
Instructions
- Preheat and prepare baking dish: Preheat the oven to 400˚F. Grease a 3-quart baking dish well with the softened butter to prevent sticking and add flavor.
- Slice vegetables: Using a mandoline or a very sharp knife, slice the sweet potatoes, parsnips, and beets into very thin rounds. Place each type of vegetable in a separate bowl to prepare individually.
- Mix vegetables with cream and seasoning: Pour 4 tablespoons of heavy cream over the sweet potatoes and parsnips each, and 2 tablespoons over the beets. Add ½ ounce grated Parmesan and 1 teaspoon minced thyme to each bowl. Season generously with salt and pepper. Toss each vegetable gently until all slices are well coated with the seasoning and cream.
- Prepare the baking dish base: Pour the remaining ¼ cup cream into the bottom of the baking dish. Sprinkle with ½ ounce of Parmesan cheese and the minced garlic to form a flavorful base layer.
- Assemble the gratin: Arrange the vegetables standing up on a bias in rows within the baking dish. Start with a row of sweet potatoes, followed by parsnips, then beets. Repeat with remaining vegetables to create six distinct rows, layering evenly.
- Season and cover: Season the top of the assembled gratin with salt, pepper, and the remaining grated Parmesan. Cover the baking dish with aluminum foil to keep moisture while baking.
- Bake covered: Bake the covered gratin for 30 minutes at 400˚F until vegetables soften and start to meld together.
- Add Gruyere and finish baking: Remove the foil and sprinkle shredded Gruyere cheese evenly over the top. Return the dish to the oven uncovered and bake for an additional 18 to 20 minutes, until the vegetables are fork-tender, the cheese has melted, and the top is lightly browned.
- Garnish and serve: Finish by sprinkling fresh thyme leaves over the gratin. Serve hot as a flavorful and elegant side dish.
Notes
- Makes one 3-quart casserole, serving approximately 8 people.
- Nutrition facts are based on the minimum quantities of vegetables listed in the ingredients for accuracy.
- This dish can be made up to a day in advance and refrigerated tightly wrapped in foil. When ready to bake, place the covered gratin in the oven, adding about 5-7 extra minutes to baking time. Note that beets may release color into the cream when stored, affecting appearance but not flavor.
- To prevent beets from bleeding color during baking: coat the sliced beets minimally with cream and use just a thin layer of cream and Parmesan on the bottom of the baking dish.
- Adjust cream quantity slightly depending on the size and surface area of your baking dish; eyeball to ensure enough coverage without excess liquid.
Nutrition
- Serving Size: 1/8 of gratin (about 1/2 cup)
- Calories: 210
- Sugar: 5g
- Sodium: 220mg
- Fat: 14g
- Saturated Fat: 8g
- Unsaturated Fat: 5g
- Trans Fat: 0g
- Carbohydrates: 18g
- Fiber: 3g
- Protein: 7g
- Cholesterol: 40mg
