Description
A rich and comforting Cheesy Root Vegetable Gratin perfect for Thanksgiving dinner, featuring layers of sweet potatoes, parsnips, and beets baked in a creamy Parmesan sauce with thyme and Gruyere cheese.
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 creamier with heavy cream)
- 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 Dish: Preheat your oven to 400˚F (200˚C). Grease a 3-quart baking dish generously with softened butter to prevent sticking and add richness.
- Slice Vegetables: Using a mandoline or sharp knife, slice the sweet potatoes, parsnips, and beets into very thin rounds. Transfer each vegetable type into its own separate bowl for seasoning.
- Season Vegetables: Pour 4 tablespoons of heavy cream each over the 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, then toss to coat each vegetable slice evenly with the cream and seasoning mixture.
- Layer Cream and Garlic in Dish: Pour the remaining ¼ cup (4 tablespoons) of heavy cream into the bottom of the prepared baking dish. Sprinkle with ½ ounce of grated Parmesan and the minced garlic, spreading evenly to create a flavorful base layer.
- Arrange the Vegetables: Starting at the top edge of the baking dish, stand a row of sweet potato slices on a bias. Follow with a row of parsnips, then a row of beets. Continue alternating rows of sweet potatoes, parsnips, and beets to create six rows total, filling the dish neatly with layered root vegetables.
- Season and Cover: Lightly season the top of the arranged gratin with salt, pepper, and sprinkle the remaining grated Parmesan cheese over the vegetables. Cover the baking dish tightly with aluminum foil to keep moisture in during the initial baking phase.
- Bake Covered: Bake the gratin in the preheated oven for 30 minutes, or until the vegetables begin to soften.
- Add Gruyere and Continue Baking: Remove the foil and evenly sprinkle the shredded Gruyere cheese over the top. Return the dish to the oven uncovered and bake for an additional 18 to 20 minutes, or until the vegetables are fork tender, the cheese has melted fully, and the top is lightly browned and bubbly.
- Finish and Serve: Remove the gratin from the oven and sprinkle with fresh thyme leaves for garnish. Serve warm as a delicious side dish to your Thanksgiving meal.
Notes
- Makes one 3-quart casserole, serving approximately 8 people.
- Nutrition facts are based on the lowest amount specified for each vegetable.
- Can be made up to one day ahead and refrigerated tightly wrapped in foil. When ready to bake, place covered in oven, adding 5-7 extra minutes baking time.
- Beets may bleed color when prepared ahead, which does not affect flavor but may alter appearance.
- To minimize beet bleeding, coat them sparingly with cream and ensure the dish bottom is just lightly covered with cream and Parmesan.
- Amounts of cream may vary slightly depending on the baking dish size; adjust visually for even coating without excess liquid.
Nutrition
- Serving Size: 1/8 of gratin (about 1 cup)
- Calories: 280 kcal
- Sugar: 7 g
- Sodium: 250 mg
- Fat: 18 g
- Saturated Fat: 10 g
- Unsaturated Fat: 6 g
- Trans Fat: 0.3 g
- Carbohydrates: 22 g
- Fiber: 4 g
- Protein: 8 g
- Cholesterol: 55 mg
