Cheesy Butternut Squash Casserole
The ultimate savory Butternut Squash Casserole with Parmesan-creamed kale, nutty Gruyere cheese, and a toasted walnut-sourdough topping. This stunning side dish will be the hit of your next holiday gathering.
Prep Time20 minutes mins
Cook Time35 minutes mins
Total Time1 hour hr
Course: Side Dish
Cuisine: American
Diet: Vegetarian
Servings: 8 people
- 4 Tbsp. extra-virgin oive oil, divided
- 1 medium yellow onion, finely chopped
- 5 garlic cloves, minced
- 1/4 to 1/2 tsp. crushed red pepper flakes (depending on desired level of heat)
- 1 bunch lacinato kale, stems and ribs removed, chopped
- 1 cup heavy cream
- 1/3 cup, plus 2 Tbsp. grated Parmesan cheese, divided
- 1 Tbsp. Dijon mustard
- 1 Tbsp. fresh thyme leaves
- 3/4 tsp. kosher salt
- 1/2 tsp. black pepper
- 2 lbs. peeled and cubed butternut squash
- 1/2 cup shredded Gruyere or gouda cheese
- 2 cups torn or roughly chopped sourdough bread
- 1/3 cup finely chopped walnuts
Preheat oven to 425ºF.Heat 2 Tbsp. olive oil in a large sauté pan over medium heat. Once hot, add onion; cook for 7 to 8 minutes, until soft. Stir in garlic and red pepper flakes; cook 2 more minutes. Stir in kale and cook until softened, about 2 to 3 minutes. Stir in heavy cream, 1/3 cup Parmesan cheese, Dijon mustard, fresh thyme, salt and pepper; simmer mixture until thickened, about 3 to 5 minutes.
Arrange butternut squash in a greased 3-quart baking dish. Carefully pour kale mixture over butternut squash, stirring to make sure it gets into all the crevices. Scatter Gruyere cheese overtop.Cover casserole with foil and bake at 425ºF for 30 minutes, until the squash becomes nearly fork-tender. (Note: if your squash is still hard at this point, bake for an additional 10 minutes.) Meanwhile, combine sourdough, walnuts, remaining 2 Tbsp. Parmesan, 2 Tbsp. olive oil, and a small pinch of salt in a medium bowl. Massage oil into bread mixture until well-coated.Remove casserole from oven and discard foil. Scatter sourdough mixture overtop and return casserole to the oven. Bake, uncovered, for 20 more minutes, until the squash is tender and filling is thickened.Let stand 5 to 10 minutes before serving.
- To Make-Ahead: Peel and cube the butternut squash up to 3 days ahead. You can also stem and chop the kale up to 1 day ahead. Refrigerate each in a separate airtight storage container.
- Store: Cover and refrigerate leftover casserole for up to 5 days.
- To Reheat: For best results, rewarm leftovers in a baking dish in the oven at 350ºF. You can reheat in the microwave in a pinch.
- To Freeze: Freeze casserole in an airtight freezer-safe storage container for up to 3 months. Let thaw overnight in the refrigerator before reheating in a 350ºF oven.
Serving: 0.75cup | Calories: 376kcal | Carbohydrates: 39g | Protein: 8g | Fat: 26g | Saturated Fat: 9g | Sodium: 425mg | Fiber: 5g | Sugar: 12g