Root Vegetable Gratin with Sweet Potatoes, Parsnips, and Beets Recipe
Introduction
Root Vegetable Gratin with Sweet Potatoes, Parsnips, and Beets is a comforting, colorful dish perfect for showcasing fall flavors. Creamy, cheesy, and fragrant with garlic and thyme, it makes a lovely side or a satisfying vegetarian main.

Ingredients
- 2 medium sweet potatoes, peeled and thinly sliced
- 2 medium parsnips, peeled and thinly sliced
- 2 medium beets, peeled and thinly sliced
- 3 cloves garlic, minced
- 1 ½ cups heavy cream
- 1 cup shredded Gruyère cheese (or sharp cheddar)
- 1 tsp thyme (fresh or dried)
- 2 tbsp olive oil
- Salt and pepper to taste
Instructions
- Step 1: Preheat the oven to 375°F (190°C) and grease a 9×13-inch baking dish with olive oil.
- Step 2: Peel and slice the sweet potatoes, parsnips, and beets into 1/8-inch thick rounds for even cooking.
- Step 3: In a saucepan, combine the heavy cream, minced garlic, thyme, salt, and pepper. Heat gently and simmer for 3–5 minutes to infuse the flavors.
- Step 4: Arrange the sliced vegetables in the baking dish, layering them by alternating colors for a vibrant presentation. Pour the warm cream mixture evenly over the layers.
- Step 5: Sprinkle the shredded Gruyère cheese over the top and cover the dish with foil to retain moisture while baking.
- Step 6: Bake the gratin covered for 35 minutes. Then remove the foil and bake for an additional 20–25 minutes until the top is bubbly and golden brown.
- Step 7: Allow the gratin to rest for 10 minutes before serving to let the layers set for easier slicing.
Tips & Variations
- Use a mandoline slicer for uniform vegetable slices to ensure even cooking and a beautiful layered look.
- Try adding a pinch of nutmeg or smoked paprika to the cream for a subtle spice twist.
- Swap Gruyère for mozzarella or fontina cheese for a different, yet delicious, flavor profile.
- For a lighter version, replace half the heavy cream with whole milk.
Storage
Store any leftovers in an airtight container in the refrigerator for up to 3 days. Reheat gently in the oven at 350°F (175°C) until warmed through, or microwave individual portions. The gratin may firm up after refrigeration, so allow it to come to room temperature before reheating for best texture.
How to Serve

Serve this delicious recipe with your favorite sides.
FAQs
Can I prepare this gratin ahead of time?
Yes, you can assemble the gratin a few hours in advance and keep it covered in the refrigerator until ready to bake. Just add a few extra minutes to the baking time if baking straight from cold.
What can I serve with this root vegetable gratin?
This gratin pairs wonderfully with roasted meats, grilled chicken, or a fresh green salad for a well-rounded meal.
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Root Vegetable Gratin with Sweet Potatoes, Parsnips, and Beets Recipe
- Total Time: 1 hour 20 minutes
- Yield: 6 servings 1x
- Diet: Vegetarian
Description
This Root Vegetable Gratin is a comforting and colorful dish featuring layers of sweet potatoes, parsnips, and beets baked in a savory garlic-thyme cream sauce and topped with melted Gruyère cheese. Perfect as a flavorful side or a vegetarian main, it offers a harmonious balance of sweetness and earthiness with a creamy texture and a golden, bubbly finish.
Ingredients
Vegetables
- 2 medium sweet potatoes, peeled and thinly sliced
- 2 medium parsnips, peeled and thinly sliced
- 2 medium beets, peeled and thinly sliced
Seasoning and Sauce
- 3 cloves garlic, minced
- 1 ½ cups heavy cream
- 1 tsp thyme (fresh or dried)
- Salt and pepper to taste
Topping and Oil
- 1 cup shredded Gruyère cheese (or sharp cheddar)
- 2 tbsp olive oil
Instructions
- Preheat and prepare dish: Preheat your oven to 375°F (190°C) and grease a 9×13-inch baking dish with olive oil to prevent sticking and ensure easy serving.
- Slice vegetables: Peel and thinly slice the sweet potatoes, parsnips, and beets into approximately 1/8-inch rounds for even layering and cooking.
- Prepare cream sauce: In a saucepan, combine the heavy cream with minced garlic, thyme, salt, and pepper. Heat the mixture over medium heat and let it simmer gently for 3 to 5 minutes to infuse the flavors.
- Layer vegetables: Arrange the sliced vegetables in the prepared baking dish, alternating colors such as sweet potato, parsnip, and beet to create an attractive layered pattern. Pour the warm cream mixture evenly over the layered vegetables to moisten and flavor them.
- Add cheese and cover: Sprinkle the shredded Gruyère cheese evenly over the top of the layered vegetables and cream. Cover the baking dish tightly with aluminum foil to retain moisture during baking.
- Bake covered: Place the gratin in the oven and bake covered for 35 minutes to allow the vegetables to soften and the flavors to meld.
- Uncover and finish baking: Remove the foil and continue baking for an additional 20 to 25 minutes until the gratin is bubbly and topped with a golden-brown crust.
- Rest before serving: Let the gratin rest for about 10 minutes after removing from the oven to allow the layers to set, making it easier to serve and enhancing the flavors.
Notes
- For a richer flavor, consider using fresh thyme rather than dried.
- You can substitute Gruyère with sharp cheddar or another melting cheese of your choice.
- Slice vegetables uniformly for even cooking and an attractive presentation.
- Letting the gratin rest before serving helps the layers hold together better.
- This dish can be prepared a day ahead and reheated before serving.
- Prep Time: 20 minutes
- Cook Time: 60 minutes
- Category: Side Dish
- Method: Baking
- Cuisine: American
Keywords: root vegetable gratin, sweet potato gratin, parsnip recipe, beet gratin, vegetarian side dish, baked vegetable casserole

