Description
This Cheesy Root Vegetable Gratin is a comforting and elegant side dish perfect for Thanksgiving dinner. Layers of thinly sliced sweet potatoes, parsnips, and beets are delicately coated in a creamy herb-infused sauce, topped with melted Gruyere and Parmesan cheese, then baked to golden perfection. The combination of root vegetables with rich dairy and fresh thyme delivers a flavorful, hearty dish that beautifully complements any festive meal.
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 substituted but creaminess will be reduced)
- 4 ounces grated Parmesan cheese, divided
- 1 ounce shredded Gruyere cheese
Herbs & Seasonings
- 1 tablespoon fresh minced thyme, divided plus extra for garnish
- 1 garlic clove, minced
- Salt and pepper, to taste
Instructions
- Preheat and Prepare Dish: Preheat your oven to 400°F. Grease a 3-quart (oval) baking dish with the softened butter to prevent sticking and add flavor.
- Slice Vegetables: Using a mandoline or knife, slice the sweet potatoes, parsnips, and beets into very thin rounds. Transfer each vegetable to its own separate bowl to prepare individually.
- Season Vegetables: Pour 4 tablespoons of heavy cream over the sweet potatoes and another 4 tablespoons over the parsnips. Pour 2 tablespoons cream over the beets. To each bowl, add ½ ounce grated Parmesan, 1 teaspoon minced thyme, and season generously with salt and pepper. Toss gently to fully coat all slices in the creamy mixture.
- Prepare Baking Dish Base: Pour the remaining ¼ cup (4 tablespoons) of cream into the bottom of the prepared baking dish. Sprinkle with ½ ounce of Parmesan cheese and the minced garlic, evenly distributing the flavors.
- Assemble Gratin Layers: Starting at one end of the baking dish, stand the sweet potato slices upright on a bias, forming the first row. Follow with a row of parsnips standing upright, then a row of beets. Repeat the layering with the remaining vegetable slices to create six rows of root vegetables neatly organized.
- Season and Cover: Season the top with additional salt, pepper, and sprinkle the remaining Parmesan cheese over the layered vegetables. Cover the dish tightly with foil to retain moisture during the initial baking.
- First Bake: Bake the covered gratin in the preheated oven for 30 minutes, or until the vegetables begin to soften.
- Top with Gruyere and Continue Baking: Uncover the gratin and sprinkle the shredded Gruyere evenly on top. Return the dish to the oven, uncovered, and bake for an additional 18 to 20 minutes. The gratin should be fork tender, the cheese melted, and the top slightly browned.
- Garnish and Serve: Remove the gratin from the oven, sprinkle with fresh thyme leaves for a final aromatic touch, and serve warm as a delicious side dish.
Notes
- Makes 1 (3-quart) casserole, serving 8 people.
- Nutrition facts are calculated based on the lowest quantities of the vegetable ranges provided.
- This gratin can be prepared up to a day in advance and refrigerated tightly wrapped in foil. When ready to bake, place the covered dish in the preheated oven, adding 5-7 minutes extra baking time while covered.
- When prepping ahead, be aware that beet juice may bleed into the cream, altering the dish’s appearance but not its flavor.
- To minimize beet bleeding, coat beet slices lightly with cream and ensure the baking dish bottom has only a thin cream layer with Parmesan.
- Cream amounts may vary slightly depending on your baking dish size; use your judgment to ensure vegetables remain moist but not swimming in cream.
Nutrition
- Serving Size: 1/8 of casserole (approx. 1 cup)
- Calories: 280
- Sugar: 6g
- Sodium: 320mg
- Fat: 20g
- Saturated Fat: 12g
- Unsaturated Fat: 6g
- Trans Fat: 0g
- Carbohydrates: 20g
- Fiber: 3g
- Protein: 8g
- Cholesterol: 65mg
