Spaghetti Squash Lasagna Recipe: Low-Carb Cheesy Layered Bake

Vegetarian Spaghetti Squash Lasagna offers a lighter, vegetable-forward twist on classic lasagna. Serve it with garlic bread for a cozy, satisfying meal.

Roasted spaghetti squash replaces traditional noodles in this layered, cheesy lasagna. Strands of squash alternate with a creamy ricotta mixture, sautéed vegetables, marinara, and melted Italian blend cheese to create a dish that’s rich in flavor but lighter than a pasta-based lasagna.

It takes a bit more time than a quick weeknight dinner, but it’s a rewarding weekend cooking project that yields a comforting, vegetable-packed entrée.

Ingredients

• One medium spaghetti squash — the substitute for pasta
• Sautéed vegetables: shallot, mushrooms, red pepper, and baby spinach
• A creamy ricotta mix with fresh basil, milk, and part of a shredded Italian cheese blend
• Marinara sauce and remaining shredded Italian blend cheese for topping
• Seasonings: dried oregano, red pepper flakes, and kosher salt

How it comes together

Begin by roasting the spaghetti squash whole to retain moisture and flavor. Depending on size, roast for 60–75 minutes at 375°F, until the squash is tender when pierced. Let it cool slightly before halving and removing seeds.

Use a fork to scrape the squash into spaghetti-like strands. To prevent a watery lasagna, remove excess moisture by placing the strands in a clean kitchen towel and wringing until no more liquid escapes. Toss the drained strands with ½ teaspoon of salt.

While the squash roasts, sauté the vegetables. Heat olive oil in a large sauté pan over medium heat. Cook minced shallot and chopped mushrooms until the mushrooms release their liquid and soften. Add diced red pepper and cook 3–4 minutes more, then add baby spinach and cook until wilted. Stir in ½ teaspoon dried oregano, ½ teaspoon red pepper flakes, and ¼ teaspoon salt, and continue cooking until the mixture is fairly dry so it won’t water down the lasagna.

For the ricotta layer, combine ricotta with ½ cup of the shredded Italian blend cheese, ¼ cup milk to loosen, and a chiffonade of fresh basil. Stir until smooth; the milk keeps the filling vegetarian-friendly, though an egg could be used for a firmer set if preferred.

Assembling the lasagna

Raise the oven temperature to 400°F before baking the assembled dish. Grease an 8×8 inch baking dish and spread ½ cup marinara sauce across the bottom. Assemble layers in the following order for an even distribution of ingredients:

1. ½ cup marinara sauce
2. ⅓ of the spaghetti squash strands
3. ½ of the ricotta mixture
4. ½ of the sautéed vegetables
5. ⅓ of the spaghetti squash
6. Remaining ricotta
7. Remaining vegetables
8. Final ⅓ of the spaghetti squash
9. Remaining marinara sauce and the rest of the shredded Italian blend cheese on top

Cover the dish with foil (placing a few toothpicks in the cheese layer helps prevent the foil from sticking) and bake for 30 minutes. Remove the foil, switch the oven to broil, and broil 6–8 minutes or until the cheese is golden and bubbly. Let the lasagna rest for about 10 minutes before slicing and serving. Garnish with extra fresh basil if desired.

This lasagna pairs nicely with crusty bread and a simple side—though it’s already full of vegetables, roasted potatoes or a crisp salad are great options for a complete meal.

Recipe

Ingredients

• 1 medium spaghetti squash
• 1 tablespoon olive oil
• 1 shallot, minced
• 10 oz button mushrooms, chopped
• 1 red pepper, diced into ½-inch pieces
• 1 (6 oz) bag baby spinach
• ½ teaspoon dried oregano
• ½ teaspoon red pepper flakes
• 1 teaspoon kosher salt, divided
• 15 oz ricotta
• ¼ cup milk
• 1 oz fresh basil, chiffonade
• 1¼ cups marinara sauce
• 1½ cups shredded Italian blend cheese, divided

Instructions

• Preheat the oven to 375°F.
• Poke holes in the spaghetti squash and bake on a sheet for 60–75 minutes, until soft. Cool, halve, and remove seeds.
• Heat olive oil in a large sauté pan over medium heat. Add shallot and mushrooms; cook until mushrooms are soft and their liquid has released.
• Add red pepper and cook 3–4 minutes. Add spinach and cook until wilted. Stir in oregano, red pepper flakes, and ¼ teaspoon salt; cook until the mixture is fairly dry.
• Scrape squash strands with a fork. Place strands in a clean towel and wring out excess water; transfer to a bowl and toss with ½ teaspoon salt.
• Combine ricotta, ½ cup shredded cheese, milk, basil, and remaining ¼ teaspoon salt in a bowl and stir to combine.
• Increase oven temperature to 400°F. Grease an 8×8 inch baking dish and pour ½ cup marinara into the bottom.
• Layer ingredients as directed in the assembly list above, finishing with the remaining marinara and shredded cheese.
• Cover with foil and bake 30 minutes. Remove foil and broil 6–8 minutes until cheese is golden in spots.
• Let cool 10 minutes, garnish with fresh basil, slice, and serve.

Notes

Make sure both the squash and the sautéed vegetables are well drained of liquid to avoid a watery lasagna. If you prefer a firmer ricotta layer, you can substitute one egg for the milk.

Nutrition (per serving)

Calories: 309 • Carbohydrates: 21 g • Protein: 19 g • Fat: 18 g • Fiber: 5 g • Sodium: 950 mg

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