Description
A rich and creamy Cheesy Root Vegetable Gratin perfect for Thanksgiving dinner, featuring thinly sliced sweet potatoes, parsnips, and beets layered and baked in a blend of heavy cream, Parmesan, Gruyere, garlic, and fresh thyme for a comforting and elegant side dish.
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
- 1 tablespoon unsalted butter, softened
- 14 tablespoons heavy cream, divided (whole milk can be used but with less creaminess)
- 4 ounces grated Parmesan, divided
- 1 ounce shredded Gruyere
Herbs & Seasonings
- 1 tablespoon fresh minced thyme, divided plus more for garnish
- 1 garlic clove, minced
- Salt and pepper to taste
Instructions
- Preheat and prepare dish: Preheat the oven to 400˚F. Grease a 3-quart baking dish with the softened butter to prevent sticking and add flavor.
- Slice vegetables: Using a mandoline or sharp knife, slice the sweet potatoes, parsnips, and beets into very thin rounds. Transfer each type of vegetable to its own separate bowl to prepare them individually.
- Coat vegetables with cream and seasonings: Pour 4 tablespoons of cream over each bowl of sweet potatoes and parsnips, 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 and toss carefully to coat all slices evenly.
- Prepare baking dish base: Pour the remaining ¼ cup (4 tablespoons) of cream into the bottom of the greased baking dish. Sprinkle with ½ ounce of Parmesan and the minced garlic to create a flavorful base layer.
- Assemble the gratin: Arrange the sweet potato slices standing on a bias in a row at the top of the baking dish. Follow with a row of parsnips and then a row of beets. Repeat this pattern with the remaining vegetables until you have approximately 6 rows, making a colorful layered effect.
- Season and cover: Season the top of the layered vegetables with salt, pepper, and sprinkle the remaining Parmesan cheese over the top. Cover the dish tightly with aluminum foil to help the vegetables cook evenly and retain moisture.
- Bake covered: Place the covered dish in the oven and bake for 30 minutes, or until the vegetables start to soften, indicating they are partially cooked through.
- Add Gruyere and finish baking: Remove the foil and scatter the shredded Gruyere evenly over the top. Return the dish uncovered to the oven and bake for an additional 18 to 20 minutes, until the vegetables are fork tender, cheese has melted, and the gratin top is lightly browned and bubbly.
- Garnish and serve: Sprinkle fresh thyme leaves over the finished gratin for a burst of herbal aroma. Serve warm as a decadent side dish for Thanksgiving dinner or any festive occasion.
Notes
- Makes 1 (3 quart) casserole suitable for about 8 servings.
- Nutrition facts are based on the lowest number of vegetables in the ingredient ranges to ensure accuracy.
- This dish can be prepared up to a day ahead of time and refrigerated tightly wrapped in foil. When ready to bake, return covered to the oven and increase baking time by 5-7 minutes.
- Be aware that if prepped ahead, the beets may bleed into the cream, altering the appearance but not the flavor.
- To minimize beet bleeding, coat the sliced beets very lightly with cream and make sure the bottom layer of the baking dish has just a thin cream layer sprinkled with Parmesan.
- Cream quantities may vary slightly depending on your baking dish surface area; it’s best to visually ensure a thin coating rather than a puddle.
Nutrition
- Serving Size: 1/8th of casserole
- Calories: 280
- Sugar: 6g
- Sodium: 260mg
- Fat: 20g
- Saturated Fat: 12g
- Unsaturated Fat: 7g
- Trans Fat: 0g
- Carbohydrates: 18g
- Fiber: 3g
- Protein: 8g
- Cholesterol: 60mg
