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Spaghetti Squash Lasagna Boats

Transform a simple squash into deliciously cheesy lasagna! Spaghetti Squash Lasagna Boats have a creamy spinach filling and a hint of Italian herbs. Easy to make with your Instant Pot, this recipe is everything you love about lasagna, without the carbs!

Love Italian food but not the sugar and flour? This Crustless Pizza Casserole is fantastic. All the great pizza toppings without the extra carbs!

Spaghetti squash halves in a baking dish topped with melted cheese.

Easy Instant Pot Dinner Recipe

You’ve probably used spaghetti squash as a stand-in for regular noodles by now–but did you know you can use it to make lasagna too?

Okay, it’s not quite lasagna in the purest sense. There’s no layering of noodles, sauce and cheese in a baking dish. This recipe is even easier than that!

By stuffing a whole spaghetti squash with veggies, cheese, sour cream and herbs, you create a satisfying, low carb alternative that has all the amazing taste of a classic lasagna. Use your instant pot to cook the spaghetti squash, then stuff it with all the fillings and bake until bubbly.

Spaghetti Squash Lasagna Boats make for an easy and hearty weeknight meal. Full of protein and good-for-you greens, this is is a healthy low-carb AND vegetarian meal that the whole family loves.

This delicious recipe comes from the Meal Prep in an Instant by Becca Ludlum! You can snag yourself a copy on Amazon if you’d like! You could also try this delicious Instant Pot Gyro recipe from the book, and just skip the pitas and eat as a bowl or salad instead!

Ingredient Notes

Ingredients needed to make Spaghetti squash lasagna boats.
  • Spaghetti Squash – Choose a smaller sized squash to make sure it fits in your Instant Pot. Cut it in half lengthwise and remove the seeds first.
  • Marinara Sauce – Check the label to ensure no added sugars. We like Rao’s brand of marinara.
  • CauliflowerChopped into pieces small enough to fit into the squash.
  • Mozzarella Cheese – Buy in a block and shred it yourself for easier melting.

Easy Instructions

Step by step photos showing how to cook squash in the instant pot.

First, you’re going to fill your cut and seeded squash with chopped cauliflower. Pressure cook the stuffed squash (stuffed side up) in the trivet of an Instant Pot filled with 2 cups of water.

While the squash is cooking, get the filling ingredients ready. Use a blender or food processor to combine cottage cheese, sour cream, garlic and herbs until smooth.

Once the spaghetti squash is done cooking, let the pot naturally release for 10 minutes then do a quick release of remaining pressure. Scoop out the cooked cauliflower and use a fork to mash it into the cottage cheese mixture.

Transfer the squash to a baking dish and scoop out the flesh (leave behind enough to support the shell!). Add the cooked spaghetti squash to the cauliflower and cottage cheese and combine. Spoon the creamy mixture back into the hollowed out squash.

Step by step photos showing how to layer lasagna in spaghetti squash.

Layer the stuffed squash halves with marinara sauce, fresh spinach and mozzarella cheese. Place it under the broiler for a minute or two until the cheese it melted, bubbly and slightly browned.

Serve hot!

Tips and Tricks

  • Want a little spice with your lasagna boats? A sprinkle of crushed red pepper flakes on top is delicious!
  • When in doubt, err on the side of undercooking your squash. You can always put it back in the Instant Pot if it isn’t done to your liking. It’s much harder to work with an overdone squash that’s mushy!
  • For more protein, serve lasagna boats with a side of grilled chicken.
Spaghetti squash lasagna boats with cookbook and instant pot in background.

Recipe FAQs

Can you freeze spaghetti squash lasagna?

Yes, you can freeze your Spaghetti Squash Lasagna Boats. Store in a freezer safe bag or container and wrap with foil for extra freshness. It keeps well in the freezer for up to 2 months.

What’s the best way to store leftovers?

The best way to store any leftovers is covered in the fridge for up to 3 days. You can also freeze them (see above)!

What size Instant Pot do I need?

You’ll need a 6 quart Instant Pot to make this recipe.

Is this recipe Keto friendly?

Yes, this recipe is suitable for folks on a Keto diet. Spaghetti squash is low in carbohydrates making it an excellent swap for other winter squashes.

More No Sugar No Flour Dinners

Yield: 2 servings

Spaghetti Squash Lasagna Boats

Transform a simple squash into deliciously cheesy lasagna! Spaghetti Squash Lasagna Boats have a creamy spinach filling and a hint of Italian herbs. Easy to make with your Instant Pot, this recipe is everything you love about lasagna, without the carbs!

Transform a simple squash into deliciously cheesy lasagna! Spaghetti Squash Lasagna Boats have a creamy spinach filling and a hint of Italian herbs. Easy to make with your Instant Pot, this recipe is everything you love about lasagna, without the carbs!

Prep Time 10 minutes
Cook Time 9 minutes
Additional Time 20 minutes
Total Time 39 minutes

Ingredients

  • 1 small spaghetti squash, halved and seeded
  • 1 1/2 cups chopped cauliflower
  • 1/4 cup cottage cheese
  • 1/4 cup sour cream
  • 1 1/2 teaspoon minced garlic
  • 1 teaspoon dried basil
  • 1 teaspoon dried oregano
  • 1/2 teaspoon dried parsley
  • 1/4 cup marinara sauce
  • 1/2 cup spinach
  • 1/4 cup shredded mozzarella cheese

Instructions

    1. Wash and cut your spaghetti squash in half.  Remove the seeds.
    2. Place a trivet in the bottom of the Instant Pot and add 2 cups of water.
    3. Put both halves of the spaghetti squash flat on the trivet, scooped side up.  If they don’t fit, you can lean them up against the sides.
    4. Fill the scooped out middles of the spaghetti squash with the chopped cauliflower.  It’s ok if some falls into the water.  The pot can be drained later to get any that falls to the bottom of the pot.
    5. Close and lock the lid.  Make sure the valve is set to SEALING.  Select the manual or HIGH PRESSURE setting and set the cook time for 6-7 minutes.  This depends largely on the size of your spaghetti squash. 
    6. While the squash is cooking, place the cottage cheese, sour cream, garlic, basil, oregano and parsley in a blender or food processor and blend until smooth - about 30 seconds.  Transfer the mixture to a medium mixing bowl.
    7. When the cook time has ended for the squash, let the pressure naturally release for 10 minutes and then do a manual quick release.  
    8. Scoop out the cooked cauliflower first and add it to bowl with the cottage cheese mixture.  Mash with a fork until combined.
    9. Carefully lift the trivet out of the Instant Pot and transfer the squash to a baking dish.  If there is any cauliflower that has spilled out of the squash and is in the bottom of the Instant Pot, drain the pot and add the rest to the bowl.
    10. Preheat the broiler on high.
    11. Hollow out each half of the squash with a fork, leaving about a ¼” of flesh behind to support the shell.  Add cooked squash to the bowl with the cauliflower and cottage cheese mixture and stir until combined.
    12. Spoon the squash mixture back into each of the shells, dividing it equally between them.  Next, add a layer of pasta sauce.  Then add a layer of spinach and lastly, sprinkle with mozzarella cheese.
    13. Place the baking dish under the broiler for about 1-2 minutes or until the cheese is bubbly and begins to brown slightly.
    14. Store in the refrigerator for up to 3 days or freeze for up to 2 months.

Notes

  • Recipe tested in a 6qt Instant Pot.
  • Be sure to check labels for no sugar added. We love Rao's brand marinara.
  • For a little extra spice, sprinkle crushed red pepper flakes when serving.
  • Add a side of grilled chicken if you want more protein.
  • Squash- be sure to choose one on the smaller side, so it will fit in the Instant Pot. Err on the side of undercoooking the squash. You could always put it back in the Instant Pot if it's not completely done.
  • Recipe written with permission from "Meal Prep in an Instant" by Becca Ludlum

Nutrition Information:

Yield:

4

Serving Size:

1 fourth squash

Amount Per Serving: Calories: 150Total Fat: 6gSaturated Fat: 3gTrans Fat: 0gUnsaturated Fat: 2gCholesterol: 15mgSodium: 229mgCarbohydrates: 22gFiber: 6gSugar: 9gProtein: 7g

You’ll love this creative spaghetti squash meal! Fire up your Instant Pot and make low-carb, sugar-free, flour-free Lasagna Boats for dinner tonight!

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