Cheesy Butternut Squash Casserole

This cheesy butternut squash casserole brings cozy comfort to the table with layers of rich vegetables loaded with flavor and gooey cheese. Whether you are after something hearty for a dinner side or a lighter vegetarian main, it delivers all the satisfaction of classic comfort food but with an extra boost of nutrition.

This dish won over my family during a chilly autumn night when we wanted something comforting but not heavy or fussy. Ever since, it has been my go-to for potlucks and holiday spreads.

Gather Your Ingredients

• Extra-virgin olive oil: Choose a fresh bottle for a fruity mellow flavor that is not bitter
• Yellow onion: Provides sweetness and depth once slowly cooked finely chopped for best texture
• Garlic cloves: Use plump cloves for a punchy aromatic note that really infuses the whole casserole
• Crushed red pepper flakes: Control the heat to your preference just a pinch brings warmth
• Lacinato kale: Look for crisp dark green leaves removes ribs for tenderness and earthy flavor
• Heavy cream: Creates richness opt for a high-fat version for silkier results
• Parmesan cheese: Adds salty depth best freshly grated and divided for sauce and topping
• Dijon mustard: Lends tangy backbone and sharpens flavors go for a smooth stone-ground style
• Fresh thyme leaves: Bright herbal note buy fresh sprigs if possible and pick leaves before using
• Kosher salt and black pepper: Season for balance taste as you go and use a coarse salt for best seasoning
• Butternut squash: Firm bright orange flesh yields a naturally sweet flavor peel and cube uniformly
• Gruyere or gouda cheese: Both options melt beautifully and boost the luxurious creamy texture
• Sourdough bread: A sturdy loaf like sourdough forms a crunch on top tear or cut into rustic chunks
• Walnuts: Offer crunch and toastiness chop finely but avoid pre-chopped for best flavor

How to Make It

Prep The Pan and Aromatics:

Preheat your oven to 425 degrees Fahrenheit. Warm two tablespoons olive oil in a large sauté pan over medium heat. Add finely chopped onion and stir often for 7 to 8 minutes until the onion becomes translucent and soft. Toss in minced garlic and a pinch of red pepper flakes. Let it cook for another 2 minutes so the garlic gets fragrant but does not brown.

Wilting the Greens:

Stir the chopped lacinato kale into the onions. Sauté for 2 to 3 minutes until the kale wilts and its color deepens.

Making the Creamy Base:

Pour in the heavy cream and sprinkle in 1 third cup of the Parmesan cheese. Whisk in the Dijon mustard and scatter in the fresh thyme leaves along with the salt and pepper. Lower heat to medium-low and simmer for 3 to 5 minutes.

Preparing the Butternut Squash:

Peel and cube your butternut squash. Toss them in a bowl with the remaining two tablespoons olive oil so they get slicked and ready for roasting flavor.

Assembly:

Grab a two-quart casserole or baking dish. Spread the seasoned squash cubes in the base. Pour your creamy kale mixture over the top and toss together lightly.

Adding the Cheesy Crunch:

Sprinkle the top with shredded Gruyere or gouda cheese and the last two tablespoons of Parmesan. Scatter torn bread chunks and then the finely chopped walnuts for a deep golden crunch.

Final Bake:

Bake for 30 to 45 minutes. The top should turn golden and crusty with the squash fork-tender underneath. If you like it extra crispy, broil for 1 or 2 minutes while watching closely.

I absolutely adore how Gruyere’s nutty flavor plays off the sweetness of roasted squash. The first time we made this, we ended up eating almost the entire pan right out of the oven while laughing in the kitchen with friends.

Flavor Boosters

Let the casserole cool completely before covering well and refrigerating to keep it moist but not soggy. Reheat gently in a low oven uncovered to preserve the crispy bread topping. For longer storage, portion the casserole into individual containers and freeze for up to two months.

Serving Suggestions

Serve as a main dish with a tangy green salad or soup for a balanced vegetarian meal. As a side, it pairs beautifully with roast chicken or pork. At holiday gatherings, a squeeze of lemon on top brightens the flavors right before serving.

Creative Twists

Substitute baby spinach for kale for a milder green, and swap walnuts for pecans or pumpkin seeds. For a non-dairy version, try full-fat coconut cream and nutritional yeast to replicate creamy and cheesy notes. In spring, use tender spring greens and blanched peas. Add mushrooms or leeks for extra savory punch in fall and winter.

Letting the finished casserole rest for 10 minutes after baking makes it easier to serve. Every time this hits a potluck table, someone asks for the recipe.

Common Questions About This Recipe

→ Which cheese works best in this casserole?

Gruyere and Parmesan are recommended for their creamy melt and robust flavor profile, but gouda can be used for a milder option.

→ Can I add more greens or swap kale?

Lacinato kale is preferred for its texture, but you can substitute with baby spinach or Swiss chard for variety.

→ How do I make the topping extra crunchy?

Toss sourdough bread with olive oil and bake until golden, then add the walnuts for the last few minutes to prevent burning.

→ Can this dish be prepared ahead?

Yes, assemble the casserole up to a day ahead and refrigerate. Add the topping and bake just before serving for best texture.

→ What can I serve alongside this casserole?

Pair it with a crisp green salad or roasted poultry for a balanced, satisfying meal.