Description
A cozy and flavorful Cheesy Root Vegetable Gratin featuring layers of sweet potatoes, parsnips, and beets baked in a creamy Parmesan sauce, topped with melted Gruyere and fresh thyme – perfect for a festive Thanksgiving dinner 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 (for greasing)
- 14 tablespoons heavy cream, divided (whole milk can be substituted)
- 4 ounces grated Parmesan cheese, divided
- 1 ounce shredded Gruyere cheese
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: Preheat your oven to 400˚F. Grease a 3-quart oval baking dish with the softened butter to prevent sticking and ensure easy cleanup.
- Slice Vegetables: Using a mandoline or a sharp knife, slice the sweet potatoes, parsnips, and beets into very thin rounds. Place each type of vegetable into separate bowls to prepare for seasoning.
- Season Vegetables: Pour 4 tablespoons of heavy cream over the sweet potatoes, and separately, 4 tablespoons over the parsnips. Pour 2 tablespoons of cream over the beets. To each bowl, add ½ ounce grated Parmesan and 1 teaspoon minced thyme. Generously season each with salt and pepper, then toss gently until every slice is evenly coated.
- Prepare Baking Dish Base: Pour the remaining ¼ cup (4 tablespoons) of heavy cream into the bottom of the prepared baking dish. Sprinkle ½ ounce of grated Parmesan and the minced garlic evenly over the cream for a flavorful foundation.
- Arrange Vegetables: Begin layering the vegetables by standing sweet potato slices on a bias along the top edge of the baking dish. Follow with a row of parsnips, then a row of beets. Repeat this pattern until all slices are arranged into six rows of root vegetables, creating a visually striking and even layering.
- Season the Top: Sprinkle salt, pepper, and the remaining Parmesan cheese on top of the arranged vegetables to enhance flavor during baking.
- Bake Covered: Cover the gratin with aluminum foil and bake in the preheated oven for 30 minutes or until the vegetables are beginning to soften.
- Uncover and Add Gruyere: Remove the foil and evenly spread the shredded Gruyere cheese over the top of the gratin.
- Continue Baking Uncovered: Return the dish to the oven uncovered and bake for an additional 18 to 20 minutes. The vegetables should be fork-tender, and the cheese on top should be melted, golden, and lightly browned.
- Finish and Serve: Remove from the oven and sprinkle fresh thyme leaves over the dish as a fragrant garnish. Serve warm as a delicious Thanksgiving side dish.
Notes
- Makes one 3-quart casserole, serving approximately 8 people.
- Nutrition facts are based on the lowest amounts listed for vegetables in the ingredient ranges.
- This dish can be made up to one day ahead and refrigerated tightly wrapped in foil. When ready to bake, bake covered with foil adding 5-7 extra minutes to the cooking time.
- Be aware that if prepped ahead, beet juices may bleed into the cream, altering the gratin’s color but not the taste.
- To prevent beet bleeding, coat the sliced beets lightly with cream and ensure the bottom of the baking dish is lightly coated with cream and Parmesan.
- Cream quantities may vary slightly depending on the size and shape of your baking dish, so adjust as needed by eye.
Nutrition
- Serving Size: 1 slice (approximate, based on 8 servings)
- Calories: 220 kcal
- Sugar: 6 g
- Sodium: 220 mg
- Fat: 14 g
- Saturated Fat: 8 g
- Unsaturated Fat: 5 g
- Trans Fat: 0 g
- Carbohydrates: 20 g
- Fiber: 4 g
- Protein: 7 g
- Cholesterol: 45 mg
