Butternut Squash Spinach Mushroom Lasagna

My tiny apartment kitchen smelled like autumn the first time I made this lasagna. The squash was roasting, filling every corner with that sweet caramelized scent, while I wrestled with trying to make béchamel sauce without splashing milk everywhere. My roommate poked her head in just as I was layering everything together, and we ended up eating it straight from the pan at midnight because neither of us could wait for it to properly set.

Last winter I served this at a dinner party where two guests sworn they hated vegetarian lasagna. They went back for seconds and actually argued over who got the last corner piece. Something about how the creamy sauce melds with the roasted vegetables just makes people forget they are not eating meat.

Ingredients

• 1 medium butternut squash: Roasting the squash first concentrates its natural sweetness and creates a creamy texture that melts into the layers
• 2 tablespoons olive oil: One tablespoon for roasting the squash, another for sautéing the vegetables
• 10 oz fresh spinach: Fresh spinach wilts beautifully and holds up better than frozen in lasagna layers
• 12 oz cremini mushrooms: These have a deeper, meatier flavor than white button mushrooms
• 1 medium onion and 3 garlic cloves: The aromatic foundation that ties all the vegetables together
• 2 cups whole milk: Whole milk creates the silkiest béchamel sauce
• 3 tablespoons butter and 3 tablespoons flour: The classic roux ratio that thickens the white sauce perfectly
• 1 cup grated Parmesan: Adds salty umami notes throughout the layers
• 2 cups shredded mozzarella: Creates that irresistible cheesy golden top
• 1 cup ricotta: Adds creamy pockets between the vegetable layers
• 9-12 no-boil lasagna noodles: No-boil noodles absorb excess moisture from the vegetables while cooking
• 1 teaspoon each dried thyme and oregano: These herbs bridge the gap between the sweet squash and savory mushrooms

Instructions

Roast the squash:

Toss the cubed squash with one tablespoon olive oil, salt, and pepper, then roast at 400°F until tender and caramelized at the edges.

Sauté the vegetables:

Cook onion and garlic until translucent, add mushrooms with herbs until browned, then wilt spinach briefly.

Make the béchamel:

Whisk butter and flour into a roux, gradually add milk while stirring until thickened, then season with salt, pepper, and nutmeg.

Layer the lasagna:

Start with sauce, then noodles, squash, vegetables, ricotta, and repeat, ending with noodles topped with remaining sauce and cheeses.

Bake until golden:

Cover and bake at 375°F for 25 minutes, then uncovered for 15-20 more minutes until bubbling and browned.

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This recipe became my go-to for bringing dinner to friends after they have had a baby or during tough weeks. It reheats beautifully and somehow tastes even better the next day when all those flavors have had time to really get to know each other.

Make It Ahead

I often assemble this lasagna the day before and refrigerate it overnight, which actually improves the texture. The noodles absorb some of the sauce and the flavors meld together.

Freezing Instructions

This lasagna freezes exceptionally well, either before or after baking. I wrap it tightly in plastic and foil, then thaw overnight in the refrigerator before baking.

Serving Suggestions

A crisp green salad with acidic vinaigrette cuts through the richness of this lasagna. I also love serving it with crusty garlic bread to soak up any extra sauce.

• Let the roasted squash cool slightly before layering so it does not make the cheese melt too quickly
• Add fresh basil just before serving for a bright pop of color and flavor
• Leftovers reheat beautifully in the microwave or covered with foil in the oven

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There is something deeply satisfying about serving a vegetarian lasagna that makes everyone at the table happy, regardless of their usual eating habits.

Questions & Answers About the Recipe

→ Can I make this lasagna ahead of time?

Yes, assemble the entire lasagna up to 24 hours in advance, cover tightly, and refrigerate. Add 5-10 minutes to the baking time if baking cold from the refrigerator.

→ What can I substitute for the ricotta cheese?

Cottage cheese blended until smooth works well, or you can use additional béchamel sauce and increase the mozzarella for a creamier texture without ricotta.

→ Do I need to cook the no-boil noodles first?

No, no-boil noodles are designed to cook directly in the oven as the sauce softens them. If using regular lasagna noodles, cook them according to package instructions before layering.

→ Can I freeze this lasagna?

Absolutely. Assemble, wrap tightly in plastic and foil, and freeze for up to 3 months. Thaw overnight in the refrigerator before baking, or add 20-30 minutes to the covered baking time.

→ How do I know when the lasagna is done?

The lasagna is ready when the cheese is golden and bubbly, and you can see the sauce actively bubbling around the edges. A knife inserted in the center should come out hot.

→ Can I add protein to this dish?

Crumbed Italian sausage, ground turkey, or shredded chicken would work well. Brown the meat with the onions and mushrooms during the vegetable preparation step.