Description
This Cheesy Root Vegetable Gratin is a perfect comforting side dish for Thanksgiving dinner, featuring layers of sweet potatoes, parsnips, and beets baked in a creamy Parmesan and Gruyere sauce. The vegetables are thinly sliced and seasoned with fresh thyme and garlic, creating a rich and flavorful gratin with a beautifully browned cheesy crust.
Ingredients
Scale
Main Ingredients
- 1 tablespoon unsalted butter, softened
- 1-2 long sweet potatoes (about 2 inches thick), peeled
- 3-4 large parsnips, ends trimmed and peeled
- 3-5 small beets, peeled
Cream and Cheese Mixture
- 14 tablespoons heavy cream, divided (whole milk can be used but results in less creamy texture)
- 4 ounces grated Parmesan cheese, divided
- 1 tablespoon fresh minced thyme, divided plus more for garnish
- 1 garlic clove, minced
- 1 ounce shredded Gruyere cheese
Seasoning
- Salt and pepper to taste
Instructions
- Preheat and Prepare Dish: Preheat your oven to 400˚F (200˚C). Grease a 3-quart baking dish thoroughly with 1 tablespoon of softened unsalted butter to prevent sticking.
- Slice Vegetables: Using a mandoline or sharp knife, slice the sweet potatoes, parsnips, and beets into very thin rounds. Place each type of vegetable in its own bowl to prepare for seasoning.
- Season Vegetables: Pour 4 tablespoons of heavy cream over the sweet potatoes and parsnips each, and 2 tablespoons of cream over the beets. Add ½ ounce of grated Parmesan and 1 teaspoon of minced thyme to each respective bowl. Season generously with salt and pepper. Toss each vegetable bowl until all slices are evenly coated with cream, cheese, and seasoning.
- Prepare Baking Dish Base: Pour the remaining ¼ cup (4 tablespoons) of heavy cream into the bottom of the greased baking dish. Sprinkle with ½ ounce of grated Parmesan and minced garlic, spreading evenly on the bottom.
- Assemble the Gratin: Arrange the vegetables standing up on a bias in the baking dish, starting with a row of sweet potatoes, followed by parsnips, then beets. Repeat the rows until all vegetables are used, creating approximately six rows of layered root vegetables.
- Season the Top: Sprinkle the top of the arranged vegetables with salt, pepper, and the remaining grated Parmesan cheese for added flavor and browning.
- Bake Covered: Cover the baking dish with foil and bake in the preheated oven for 30 minutes or until the vegetables begin to soften.
- Add Gruyere Cheese: Remove the foil and sprinkle shredded Gruyere cheese evenly over the top of the gratin.
- Finish Baking Uncovered: 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 fully, and the top is lightly browned and bubbly.
- Garnish and Serve: Remove from oven and garnish with freshly sprinkled thyme leaves. Serve warm as a delicious and cheesy holiday side dish.
Notes
- Makes 1 (3 quart) casserole, serving about 8 people.
- Nutrition facts are based on using the lowest numbers for vegetable quantities in the ingredient ranges.
- This gratin can be prepared up to a day ahead and stored refrigerated, tightly wrapped with foil. When ready to bake, bake covered, adding 5-7 minutes extra baking time.
- Be aware that prepping the dish ahead may cause the beets to bleed into the cream, which affects appearance but not flavor.
- To prevent beet bleeding, coat beets sparingly with cream and ensure a thin cream layer is spread at the bottom of the baking dish with Parmesan.
- The amount of cream used can be adjusted slightly depending on the size and surface area of your baking dish.
Nutrition
- Serving Size: 1/8 of the gratin
- Calories: 280 kcal
- Sugar: 6 g
- Sodium: 320 mg
- Fat: 20 g
- Saturated Fat: 12 g
- Unsaturated Fat: 7 g
- Trans Fat: 0 g
- Carbohydrates: 18 g
- Fiber: 4 g
- Protein: 8 g
- Cholesterol: 55 mg
