This cozy Butternut Squash Gratin is the ultimate fall side dish—rich, creamy, and full of warm seasonal flavors. Tender slices of butternut squash are layered in a baking dish, covered in a silky sage-infused cream sauce, and finished with a crisp, golden Parmesan topping. Whether you’re making a Thanksgiving feast, planning a Christmas dinner, or simply craving a comforting fall side, this easy gratin is guaranteed to impress. Everyone will be asking for the recipe!
Ingredients for Butternut Squash Gratin
- 2 lb (900g) butternut squash, peeled and sliced into ⅛-inch half-moons
- 3 tbsp butter
- 1 large shallot, minced
- 4 garlic cloves, roughly chopped
- 1 tbsp all-purpose flour
- 1 cup low-sodium vegetable stock
- 1 cup heavy whipping cream
- 15 sage leaves
- ½ tsp pepper
- ½ tsp onion powder (optional)
- 3 oz (100g) grated Parmesan cheese
- Chopped chives for serving (optional)
Why You’ll Love This Butternut Gratin
- Perfect for fall & holiday menus: Butternut squash shines in baked dishes and pairs beautifully with sage, garlic, and Parmesan.
- Simple yet elegant: Easy enough for any weeknight, but impressive enough for a festive meal.
- Make-ahead friendly: Prep the sauce and squash in advance for an effortless assembly.
- Vegetarian & naturally gluten-free (just swap the flour for GF if needed).
- Crowd-pleasing flavor: Creamy center, crispy top, and incredible aroma.
How to Make Butternut Squash Gratin
1. Prepare the Squash
Peel the butternut squash, slice into thin half-rounds (about ⅛ inch thick), and remove the seeds. Try to keep the slices evenly sized so they bake evenly.
2. Cook the Shallot & Garlic
In a saucepan, melt the butter over medium heat. Add the minced shallot and chopped garlic and sauté for 1–2 minutes, until fragrant.
3. Make the Cream Sauce
Stir in the flour to form a roux. Slowly whisk in the vegetable stock until smooth.
Add the heavy cream, pepper, onion powder (optional), and sage leaves. Continue stirring—without letting it boil—until the sauce thickens slightly.
4. Assemble the Gratin
Grease a 9×13-inch baking dish with butter.
Spoon ⅓ of the cream sauce onto the bottom and sprinkle lightly with Parmesan.
Arrange the squash slices in overlapping rows.
Pour the remaining cream mixture evenly over the squash.
Cover the dish with parchment paper and foil (to prevent sticking).
5. Bake
Bake the gratin at 400°F (200°C) for 20 minutes, covered.
Remove the foil and parchment, sprinkle the remaining Parmesan over the top, and return to the oven.
Bake 10 more minutes, uncovered, until golden and bubbly.
6. Serve
Finish with fresh chives, if desired. Serve warm, straight from the baking dish.
Enjoy this cozy, creamy side!
Tips for the Best Butternut Squash Gratin
- Use fresh sage for the best flavor—it’s essential to the aroma.
- Add bacon, caramelized onions, or toasted breadcrumbs for extra richness.
- Mix in a small amount of nutmeg, rosemary, or thyme for a flavor twist.
- Make it heartier by layering bread cubes for a stuffing-style version.
- Slice squash evenly to ensure perfect tenderness throughout.
Storing Leftovers
Store leftovers in the refrigerator for up to 2 days, tightly covered.
Reheat at 350°F (180°C) until warmed through.
More Cozy Butternut Squash Recipes
- Garlic Butter Roasted Butternut Squash
- Butternut Squash Steaks with Garlic Butter
- Rosemary Garlic Sautéed Butternut Squash
- Roasted Butternut Squash
- 21 Best Butternut Squash Recipes for Fall