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 thyme sauce topped with melted Gruyère cheese. With its beautiful presentation and rich flavors, it makes a stunning addition to any holiday table.
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
- 1 tablespoon unsalted butter, softened
- 14 tablespoons heavy cream, divided (whole milk can be used but will be less creamy)
- 4 ounces grated Parmesan, divided
- 1 tablespoon fresh minced thyme, divided plus more for garnish
- 1 garlic clove, minced
- 1 ounce shredded Gruyère
- Salt and pepper to taste
Instructions
- Prep the Oven and Dish: Preheat your oven to 400˚F (200˚C). Grease a 3-quart oval baking dish with the softened butter to prevent sticking and help with browning.
- Slice the Vegetables: Using a mandoline or a very sharp knife, slice the sweet potatoes, parsnips, and beets into very thin rounds. Place each type of sliced vegetable into its own bowl to prepare for seasoning.
- Season the Vegetables: Pour 4 tablespoons of heavy cream over the sweet potatoes and parsnips each, 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 and toss gently until all slices are evenly coated.
- Prepare Gratin Base: Pour the remaining ¼ cup (4 tablespoons) of cream into the bottom of the prepared baking dish. Sprinkle with ½ ounce Parmesan and the minced garlic to add depth of flavor to the base layer.
- Assemble the Gratin: Arrange the vegetables standing up on a bias in rows inside the baking dish starting with sweet potatoes, then parsnips, then beets. Repeat the pattern until all the slices are used, creating about 6 neat rows of root vegetables.
- Final Seasoning: Season the top of the stacked vegetables with salt, pepper, and the remaining Parmesan to enhance flavor and help form a golden crust.
- Bake Covered: Cover the gratin tightly with foil and bake in the preheated oven for 30 minutes or until the vegetables have softened significantly when tested.
- Add Cheese and Finish Baking: Remove the foil, sprinkle the shredded Gruyère evenly on top, and return the dish to the oven uncovered. Bake for an additional 18 to 20 minutes until the vegetables are fully fork tender, the cheese has melted, and the top is lightly browned to perfection.
- Garnish and Serve: Remove from oven and sprinkle fresh thyme leaves on top for a fragrant finish. Serve warm as a delicious holiday side.
Notes
- Makes one 3-quart casserole, suitable for about 8 servings.
- Nutrition facts are calculated based on the lowest quantity of vegetables to stay conservative.
- This gratin can be assembled up to one day ahead and refrigerated covered with foil. Add 5-7 minutes extra baking time when cooking from chilled.
- Be aware that beets may bleed color into the cream when prepared ahead, which affects appearance but not taste.
- To prevent beet bleeding, coat beets lightly with cream only and make sure the dish’s base has a thin cream layer with Parmesan.
- Adjust cream quantity slightly depending on your baking dish size to maintain creaminess without drying out.
Nutrition
- Serving Size: 1/8 of gratin
- Calories: 280
- Sugar: 6g
- Sodium: 320mg
- Fat: 18g
- Saturated Fat: 10g
- Unsaturated Fat: 7g
- Trans Fat: 0g
- Carbohydrates: 22g
- Fiber: 4g
- Protein: 8g
- Cholesterol: 55mg
