Butternut Squash Gratin
This butternut squash gratin is creamy, comforting and one of my favorite winter side dishes. It bakes in just over an hour, with tender layers of thinly sliced butternut squash, a creamy Gruyère and sage sauce and a golden breadcrumb top. It's the type of side dish everyone goes back to the holiday table for, yet you can assemble it days in advance, so it's simple enough for even the busiest Thanksgiving.
Servings: 10 servings
Ingredients
- 2 lbs butternut squash halved, peeled and sliced 1/8 inch thick
- 1 tbsp butter
- 1 large yellow onion thinly sliced
- 3 cloves garlic minced
- 1/2 tsp salt
- 5 sage leaves thinly sliced
- 1/2 cup chicken broth
- 1 cup heavy cream
- 1/8 tsp nutmeg
- 1/4 tsp pepper
- 1 cup grated Gruyère cheese divided
- 1/4 cup breadcrumbs
Instructions
- Preheat the oven to 400°F and lightly grease an 11x7 inch baking dish.
- In a skillet on medium-high heat, melt the butter, then add the thinly sliced onion and garlic. Season with salt and sauté for 3 minutes, then add the sage and sauté for an additional 4-5 minutes until the onion has softened.
- Pour in the chicken broth and bring to a gentle simmer, then pour in the heavy cream. Stir in the nutmeg and pepper and leave to gently simmer for 5 minutes until the sauce begins to thicken. Remove from the heat and stir in 1/2 cup of the grated Gruyère until it melts into the sauce.
- Add a thin layer of butternut squash slices to the greased baking dish so they overlap slightly. Pour 1/3 of the sauce over the squash and sprinkle with half of the remaining Gruyère, then add another thin layer of squash, followed by another 1/3 of the sauce, the rest of the Gruyère and a final layer of squash. When layering, make sure everything is packed tightly together without big gaps. Top with the last of the sauce, then sprinkle the breadcrumbs over the top.
- Cover the baking dish with foil and bake for 40 minutes. Remove the foil, turn the oven to broil and cook for an additional 1-2 minutes until the breadcrumbs are golden brown, watching carefully so they don't burn.
- Remove from the oven and let the gratin rest for a few minutes before serving.
Notes
Make Ahead: You can assemble this gratin up to 3 days in advance. Cover it tightly and keep it in the fridge, then bake it straight from the fridge right before serving.
Storage: Store leftovers in an airtight container in the fridge for up to 4 days.
Reheating: Warm leftovers covered with foil in a 350°F oven until heated through, or in the microwave in short bursts.
Sweet Potato: You can swap the butternut squash for sweet potatoes, just slice them to the same 1/8 inch thickness so they cook through evenly.
Vegetarian: Use vegetable broth in place of the chicken broth.
Gluten Free: Use gluten-free breadcrumbs, and check the label on your broth.