Description
This Cheesy Root Vegetable Gratin is a perfect Thanksgiving side dish featuring sweet potatoes, parsnips, and beets layered in a creamy Parmesan and thyme sauce, topped with melted Gruyere cheese for a rich, comforting finish.
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
Gratin Base and Topping
- 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 tablespoon fresh minced thyme, divided plus more for garnish
- 1 garlic clove, minced
- 1 ounce shredded Gruyere cheese
- Salt and pepper to taste
Instructions
- Preheat and Prepare Dish: Preheat the oven to 400˚F. Grease a 3-quart baking dish with softened butter to prevent sticking and provide flavor.
- Slice Vegetables: Using a mandoline or sharp knife, slice the sweet potatoes, parsnips, and beets into very thin rounds. Place each vegetable in its own separate 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 grated Parmesan and 1 teaspoon minced thyme to each bowl. Season generously with salt and pepper and toss the slices gently to evenly coat each vegetable in the creamy mixture.
- Prepare Baking Dish Base: Pour the remaining ¼ cup (4 tablespoons) of cream into the bottom of the greased baking dish. Sprinkle ½ ounce of Parmesan and the minced garlic over the cream to add a flavorful base layer.
- Layer Vegetables: Stand a stack of sweet potato slices on a bias at the top of the baking dish, followed by a row of parsnips, then a row of beets. Continue layering to create six distinct rows, repeating the sequence until all vegetables are used.
- Season and Cover: Season the top of the vegetable arrangement with salt, pepper, and the remaining Parmesan cheese. Cover the dish tightly with aluminum foil to retain moisture during baking.
- Bake Covered: Bake the gratin covered for 30 minutes, allowing the vegetables to soften gently.
- Add Cheese Topping: Remove the foil and sprinkle the shredded Gruyere cheese over the top of the gratin evenly.
- Bake Uncovered: Return the gratin to the oven, uncovered, and continue baking for 18 to 20 minutes until the vegetables are fork-tender, the cheese has melted fully, and the top is lightly browned.
- Finish and Serve: Sprinkle fresh thyme leaves over the gratin for garnish. Serve warm as a rich and creamy holiday side dish.
Notes
- Makes 1 (3 quart) casserole suitable for about 8 servings.
- Nutrition facts are calculated using the lower end of the vegetable quantity ranges to provide a conservative estimate.
- This dish can be prepared up to a day ahead and refrigerated tightly covered with foil. When baking from refrigerated, add about 5-7 minutes to the covered baking time.
- Beets may bleed into the cream if made ahead, affecting the dish’s appearance but not the flavor.
- To minimize beet bleeding, coat them lightly with cream and ensure a thin layer of cream and Parmesan cheese is spread on the bottom of the baking dish to keep moisture balanced.
- Adjust cream amounts slightly depending on baking dish surface area to avoid dryness or excessive liquid.
Nutrition
- Serving Size: 1/8 of gratin (approx. 3/4 cup)
- Calories: 220
- Sugar: 6g
- Sodium: 210mg
- Fat: 15g
- Saturated Fat: 9g
- Unsaturated Fat: 5g
- Trans Fat: 0g
- Carbohydrates: 18g
- Fiber: 3g
- Protein: 7g
- Cholesterol: 50mg
