Butternut Sausage Casserole

The first time I made this casserole was on a rainy Sunday when my apartment felt too big and too quiet. I'd bought a butternut squash on impulse and some Italian sausage from the farmers market, not really planning anything specific. The kitchen started smelling like sage and roasting vegetables, and suddenly the whole day felt warmer.

Last winter my sister came over exhausted from work, and I pulled this bubbling dish out of the oven. She took one bite and asked if I'd been cooking all afternoon. I didn't tell her it only took twenty minutes of prep—that's our secret now.

Ingredients

• 1 medium butternut squash: Peel and cube it into 1-inch pieces so they roast evenly and soften at the same rate as everything else
• 1 pound Italian sausage: Remove the casing and break it apart thoroughly while cooking so you get those perfect crumbles throughout
• 1 medium onion: Dice it small so it melts into the background rather than staying in distinct chunks
• 2 cloves garlic: Minced fresh garlic adds that aromatic base that ties everything together
• 3 cups baby spinach: It wilts down dramatically so don't worry that it looks like too much at first
• 1 cup cooked quinoa: Use any leftover quinoa or cook it ahead—it adds this great nutty texture and makes the dish more filling
• 1 cup shredded mozzarella cheese: Sprinkle it evenly so every bite gets that satisfying cheese pull
• ½ cup grated Parmesan cheese: Adds a salty umami kick that balances the sweet squash perfectly
• 2 tablespoons olive oil: Use this to sauté your vegetables and sausage, building those flavor layers
• 1 teaspoon dried thyme: Earthy and warm, this pairs beautifully with roasted squash
• 1 teaspoon dried sage: Sage and butternut squash are basically best friends in the flavor world
• 1 teaspoon paprika: Adds a subtle warmth and gorgeous color to the dish
• Salt and pepper: Season generously but taste as you go since the sausage and cheese are already salty
• 1 cup chicken or vegetable broth: Creates a little sauce as it bakes and keeps everything from drying out

Instructions

Preheat your oven to 375°F and prep your baking dish:

Grab a 9x13-inch baking dish and give it a quick coat of cooking spray or olive oil so nothing sticks later.

Sauté the onion:

Heat the olive oil in a large skillet over medium heat and toss in the diced onion, cooking for about 5 minutes until it turns translucent and smells sweet.

Add the garlic:

Stir in the minced garlic and let it cook for just 1 minute until fragrant—don't let it brown or it'll turn bitter.

Brown the sausage:

Crank up the heat slightly and add the Italian sausage, breaking it apart with a wooden spoon until it's fully browned and cooked through, which takes about 7 to 10 minutes.

Add the squash and spices:

Toss in the butternut squash cubes along with the thyme, sage, paprika, salt, and pepper, stirring to coat everything and letting the squash start to soften for 5 to 7 minutes.

Stir in spinach and quinoa:

Add the baby spinach and cooked quinoa, stirring constantly until the spinach completely wilts into the mixture.

Add the broth and simmer:

Pour in the broth and let everything simmer together for 3 to 4 minutes, just until the liquid slightly reduces.

Transfer to baking dish:

Pour the entire mixture into your prepared baking dish and spread it out evenly so it all bakes at the same rate.

Add the cheese topping:

Sprinkle the shredded mozzarella and grated Parmesan all over the top so it'll create that gorgeous golden crust.

Bake covered first:

Cover the dish tightly with aluminum foil and bake for 25 minutes so everything steams and melds together.

Uncover and finish baking:

Remove the foil and bake for another 15 to 20 minutes until the cheese is bubbling and has turned golden brown in spots.

Let it rest before serving:

Set the casserole aside for 5 minutes so it sets up slightly and won't be too runny when you scoop it.

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This recipe has become my go-to when friends need comforting but I don't have the energy for anything complicated. Something about bubbling cheese and roasted vegetables feels like a hug in food form.

Make It Your Own

I've swapped quinoa for cooked rice when that's what I had in the fridge, and honestly the texture was still lovely. You could also use couscous or even farro if you want something chewier.

Vegetarian Swap

My plant-based friend loved this when I used crumbled plant-based sausage and vegetable broth. The flavors still work beautifully together, so don't hesitate to make it meat-free.

Plan Ahead

You can assemble the entire casserole up to 2 days before baking and keep it covered in the refrigerator. Just add about 5 to 10 extra minutes to the baking time since you're starting with cold ingredients.

• Use leftover roasted vegetables from another dinner to save even more prep time
• Double the recipe and bake two dishes—one for now and one for the freezer
• The flavors actually develop more if it sits overnight before baking

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There's something so satisfying about pulling this dish out of the oven, all golden and bubbling, and watching everyone's faces light up. That's what cooking is all about.

FAQs About This Recipe

→ Can I make this ahead of time?

Yes, assemble the entire casserole up to 2 days before baking. Cover tightly and refrigerate. Add a few extra minutes to the baking time if baking from chilled.

→ What can I substitute for the quinoa?

Cooked rice or couscous work well as alternatives. Even cooked farro or barley would add nice texture and nutty flavor.

→ Is this dish freezer-friendly?

Yes, you can freeze the assembled unbaked casserole for up to 3 months. Thaw overnight in the refrigerator before baking as directed.

→ How do I make it vegetarian?

Replace the Italian sausage with plant-based sausage crumbles or cannellini beans. Use vegetable broth instead of chicken broth.

→ What other vegetables work well?

Sweet potatoes, Brussels sprouts, or kale make great additions or substitutions based on what's in season.