Butternut Squash, Sweet Potato, and Potato Gratin Recipe

If you’re craving a dish that feels like a warm hug on a chilly afternoon, then the Butternut Squash, Sweet Potato, and Potato Gratin is your new best friend in the kitchen. This gratin brings together the natural sweetness of butternut squash and sweet potatoes with the comforting creaminess of Yukon gold potatoes, all enveloped in a luscious cheesy sauce that’s infused with fragrant herbs. Every bite reveals layers of tender vegetables bathed in rich, flavorful cream, making it the ultimate cozy side that elevates any meal effortlessly.

Ingredients You’ll Need

The beauty of this gratin lies in its simple yet thoughtfully selected ingredients. Each one plays an essential role in building flavor, texture, and that inviting golden color that makes this dish so irresistible.

• Butternut squash (2 cups, peeled & thinly sliced): Adds vibrant color and a natural sweetness that balances the savory elements.
• Sweet potatoes (2 cups, peeled & thinly sliced): Bring a creamy texture and additional sweetness with a slightly earthy tone.
• Yukon gold potatoes (2 cups, thinly sliced): Provide a buttery flavor and creamy consistency that holds the gratin together.
• Olive oil or melted butter (2 tbsp): Used to coat the veggies, enhancing richness and helping herbs stick.
• Garlic (2 cloves, minced): Infuses the dish with aromatic depth and a slight bite.
• Thyme (1 tsp, fresh or dried): Offers a subtle earthiness that pairs beautifully with root veggies.
• Rosemary (1 tsp, fresh or dried): Brings a pine-like fragrance that makes the gratin taste instantly homey.
• Salt & black pepper (to taste): Essential seasonings that make all the flavors pop.
• Heavy cream (1 cup) or half-and-half: Creates the luxurious base of the sauce that holds everything together.
• Milk (½ cup): Lightens the cream slightly, keeping the sauce smooth and silky.
• Parmesan cheese (½ cup, grated): Adds a salty, nutty punch and aids in creating a golden crust.
• Gruyère or mozzarella (½ cup, shredded): Melts beautifully, lending gooey, cheesy richness.
• Nutmeg (½ tsp): A pinch of warmth that subtly enhances the creamy sauce.
• Optional toppings: Extra Parmesan, fresh parsley or chives, and a drizzle of honey to balance sweet and savory elements.

How to Make Butternut Squash, Sweet Potato, and Potato Gratin

Step 1: Prepping the Vegetables

Start by peeling and thinly slicing the butternut squash, sweet potatoes, and Yukon gold potatoes. Using a mandoline slicer here is a game changer as it ensures even slices, which not only help everything cook uniformly but also look stunning when you layer the veggies. Toss the slices gently with olive oil or melted butter, minced garlic, thyme, rosemary, salt, and pepper. This seasoned coating is the flavor base that transforms humble root vegetables into something unforgettable.

Step 2: Preparing the Creamy Sauce

In a saucepan over gentle heat, combine the heavy cream, milk, grated Parmesan, shredded Gruyère or mozzarella, nutmeg, salt, and pepper. Stir continuously until the cheeses melt completely and the mixture is smooth and velvety. Be careful not to let it boil, as this could cause the sauce to separate. This buttery cheesy sauce is what makes the gratin decadently creamy and pulls all the layers together.

Step 3: Layering the Gratin

Grease a medium baking dish and start arranging the sliced vegetables upright, alternating between potato, sweet potato, and butternut squash slices. This layering technique not only creates a beautiful rainbow effect but also ensures each bite has a balance of flavors. Once the layers are in place, slowly pour the warmed creamy sauce over them, letting it seep in between the slices so every piece is luxuriously coated.

Step 4: Baking to Perfection

Cover the dish with foil and bake in a preheated oven at 375°F (190°C) for 35 minutes. Afterward, remove the foil and sprinkle extra Parmesan cheese on top if you love a golden crust. Bake for another 20 to 25 minutes until the gratin is bubbling and beautifully browned on top. Letting it rest for 10 minutes after baking allows the layers to set, making it easier to slice and serve.

How to Serve Butternut Squash, Sweet Potato, and Potato Gratin

Garnishes

Adding a sprinkle of fresh parsley or chopped chives at the end brightens the dish with a burst of color and a hint of herbal freshness. If you’re feeling adventurous, a light drizzle of honey balances the savory richness perfectly, giving the gratin a delightful sweet-savory twist that will impress your guests.

Side Dishes

This gratin is rich and flavorful on its own but pairs wonderfully with roasted meats like herb-crusted chicken or pork tenderloin. For a lighter meal, serve it alongside a crisp green salad dressed with a tangy vinaigrette to cut through the creaminess.

Creative Ways to Present

For a visual wow factor, layer the sliced vegetables vertically in individual ramekins instead of a large dish. This presentation allows each person to enjoy a personal portion with all the beautiful colors visible. You could also sprinkle crushed toasted nuts — like pecans or walnuts — on top just before serving, adding crunch and a nutty depth.

Make Ahead and Storage

Storing Leftovers

Once cooled, store leftover Butternut Squash, Sweet Potato, and Potato Gratin in an airtight container in the refrigerator. It will stay fresh for up to 3 days and tastes just as delicious when reheated.

Freezing

You can freeze this gratin, but to maintain the best texture, freeze it before baking. Assemble the dish, cover tightly with plastic wrap and aluminum foil, then freeze for up to 2 months. When ready to bake, cook it covered for about an hour, then uncover and bake until bubbly and golden.

Reheating

Reheat individual servings in the microwave for 2-3 minutes or warm the entire dish in a 350°F (175°C) oven, covered with foil, until heated through—about 20 minutes. Removing the foil at the end will refresh the crispy top crust.

FAQs

Can I use other types of cheese in this gratin?

Absolutely! The recipe is versatile, so feel free to swap Gruyère or mozzarella with cheeses like cheddar, fontina, or even a smoky gouda to change the flavor profile.

Is it necessary to peel the vegetables?

For the creamiest texture and smoothest mouthfeel, peeling is recommended. However, if you prefer a bit more rustic feel and added fiber, you can leave the skins on as long as the veggies are washed thoroughly.

Can I make this dish vegan or dairy-free?

Yes! Substitute the cream and milk with coconut milk or cashew cream, and use vegan cheese alternatives. Olive oil or vegan butter replaces the butter, and you’ll still get a deliciously creamy gratin.

What’s the best way to slice the vegetables evenly?

A mandoline slicer is your best friend here—it ensures uniform thin slices that cook evenly and create a beautiful layered effect. If you don’t have one, a very sharp knife and a steady hand will do.

Can I add other vegetables to this gratin?

Definitely! Thin slices of parsnips, carrots, or even zucchini can be added for extra layers of flavor and texture, just keep the layering balance in mind to ensure even cooking.

Final Thoughts

You really can’t go wrong with this Butternut Squash, Sweet Potato, and Potato Gratin—it’s a dish that brings cozy comfort and elegant flavors to your table in one satisfying package. Whether you’re serving it for a holiday feast or a quiet weeknight dinner, its creamy layers and rich textures will quickly make it a beloved staple. Give it a try, and watch it become one of your own kitchen go-tos!