Low Carb Cheesy Spaghetti Squash

This low carb cheesy spaghetti squash is tender squash strands tossed with Parmesan, Italian cheese and herbs, piled back into the shells and broiled until golden and bubbly. It's an easy, filling side dish that tastes like comfort food, and at about 8g net carbs per serving it fits right into a keto or low carb day.

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I wanted to call this recipe "twice baked," but it isn't even baked once! The squash cooks in the Instant Pot in 15 minutes, gets tossed with cheese and seasonings, and then goes back into its own shells for a quick trip under the broiler. Cooking it whole also means you don't have to wrestle a knife through a rock-hard raw squash: you cut it and scoop the seeds after it's soft.

Is Spaghetti Squash Low Carb?

Yes! One cup of cooked spaghetti squash (about 155 g) has roughly 10g of total carbs and 2g of fiber, which works out to about 8g net carbs per cup. Compare that with around 40g net carbs in a cup of cooked regular spaghetti, and it's easy to see why spaghetti squash is a favorite with low carbers. It's also only about 40 calories a cup, so there's plenty of room for butter, cheese and sauce.

It isn't zero carb, so keep an eye on portions if you're keeping your daily total very low. In this recipe a serving is a quarter of a medium squash, and with all the cheese it comes to about 8g net carbs. If you want more low carb pasta swaps, check out my roundup of Low Carb Spaghetti Alternatives.

Key Ingredients & Substitutions

• Spaghetti squash. Pick one that feels heavy for its size, with firm, matte skin and no soft spots. A medium squash (about 2 to 2 ½ pounds) gives you roughly 4 cups of strands and fits in a 6-quart Instant Pot.
• Olive oil. It coats the strands so the seasoning sticks and keeps the squash from tasting watery. Melted butter is a delicious swap. Not sure which oil to buy? My guide to olive oil for low carbers can help.
• Italian seasoning. A blend of dried oregano, basil, thyme and rosemary. I like Simply Organic Italian Seasoning, but any brand works, or mix your own from the dried herbs you have.
• Onion powder. Adds savory depth without the extra carbs and moisture of fresh onion. Garlic powder is a great addition or swap.
• Shredded Italian blend cheese. Usually mozzarella, provolone, Parmesan and Asiago. Plain mozzarella or a Mexican blend will also melt beautifully.
• Parmesan. Brings that salty, nutty flavor. Pecorino Romano or Asiago are good stand-ins. Shred it yourself from a block if you can, since it melts more smoothly.

Helpful Tips

Instant Pot is the fastest. Pierce the whole squash several times, set it on the rack over a cup of water, and cook on High Pressure for 15 minutes with a quick release. A small squash needs about 12 minutes and a large one 18 to 20. Overcooked squash goes mushy, so err on the shorter side.

Slow cooker vs. oven. No Instant Pot? A slow cooker is the most hands-off option: put the whole pierced squash in a 6-quart or larger cooker with ½ cup of water and cook on LOW for 5 to 6 hours or HIGH for 3 to 4 hours. It's perfect for busy days, though the strands come out a little softer. The oven gives you the best texture and a touch of roasted flavor: halve and seed the raw squash, brush the cut sides with oil, and roast cut side down at 400°F for 35 to 45 minutes. It takes more effort to cut a raw squash, so microwave it for 3 to 4 minutes first to soften the skin. My guide on How to Cook Spaghetti Squash walks through every method.

Let it cool before cutting. The squash is full of steam when it comes out. Give it 5 minutes before you slice it, and use an oven mitt or a clean towel to hold it steady.

Scrape lengthwise for long strands. Run your fork from end to end rather than across the squash. The strands grow in rings around the squash, so scraping along its length gives you the longest "noodles." Leave a thin layer in the shells so they keep their shape for broiling.

Watch the broiler. The cheese goes from melted to burned fast. Set the rack about 6 inches from the heat and check after 3 minutes.

Variations

• Garlic lover's. Stir 2 minced garlic cloves into the oil, or try my Garlic Butter Spaghetti Squash.
• Bacon and cheddar. Swap the Italian cheese for sharp cheddar and fold in 4 slices of crumbled cooked bacon.
• Pizza style. Add chopped pepperoni and a spoonful of sugar-free marinara, then top with mozzarella.
• Creamy. Mix in 2 ounces of softened cream cheese with the Parmesan for an extra-rich filling.
• Spinach and feta. Fold in a handful of chopped wilted spinach and use crumbled feta in place of half the Italian cheese.
• A little heat. Add a pinch of red pepper flakes, or stir in some chopped pickled jalapenos.

Serving Ideas

This cheesy squash is a hearty side that goes with just about any meat or fish. Serve it alongside roast chicken, grilled steak, pork chops, meatballs or baked salmon, and add a green salad or some roasted broccoli to round out the plate.

Served in the shells, it also looks great on a holiday table. For a meatless main, give each person half a squash and top it with a fried egg or some sauteed mushrooms.

Storing & Freezing

Let leftovers cool, then keep them in an airtight container in the fridge for up to 4 days. Reheat in the microwave for 1 to 2 minutes, or warm in a 350°F oven for about 15 minutes, with a little extra cheese on top if you like. You can also cook and shred the squash up to 3 days ahead, then mix and broil it just before serving.

You can freeze it, but the squash releases some water when it thaws, so the texture is a little softer. Freeze the cheesy strands (out of the shells) in a freezer bag for up to 3 months, thaw overnight in the fridge, drain off any liquid, and reheat in a baking dish in the oven until hot.

More Low Carb Spaghetti Squash Recipes

If you loved this recipe, here are more ways to enjoy spaghetti squash:

• Garlic Butter Spaghetti Squash
• Spaghetti Squash Au Gratin
• Low Carb Spaghetti Squash Casserole
• Pesto Spaghetti Squash
• Spaghetti Squash all'Arrabbiata
• Spaghetti Squash with Burrata and Roasted Cherry Tomatoes
• Spaghetti Squash Fritters
• Spaghetti Squash Noodle Soup
• How to Cook Spaghetti Squash

📖 Recipe

StepAwayFromTheCarbs.com

Low Carb Cheesy Spaghetti Squash

4.84 from 6 votes

Tender spaghetti squash strands tossed with Parmesan, Italian cheese and herbs, piled back into the shells and broiled until golden and bubbly. An easy low carb side dish made in the Instant Pot, with oven and slow cooker options too.

Print Recipe Pin Recipe

Prep Time 10 minutes mins

Cook Time 30 minutes mins

Total Time 40 minutes mins

Makes: 4 servings

Net Carbs: 8

Calories: 235

Ingredients Equipment Method Nutrition Notes

Ingredients

 

US CustomaryMetric

• 1 medium spaghetti squash about 2 to 2 ½ lb
• 1 cup water
• 2 tbs olive oil
• 1 teaspoon Italian seasoning
• ½ teaspoon onion powder
• salt and black pepper
• 1 cup shredded Italian blend cheese divided
• ½ cup shredded Parmesan

Equipment

• Instant Pot Duo, 6-QT, Stainless Steel/Black

Step-by-Step Instructions

 

Cook ModePrevent your screen from going dark

1. Pierce the whole spaghetti squash 8 to 10 times all over with a sharp knife or fork so steam can escape while it cooks.
2. Set the steam rack inside the Instant Pot and pour in the water. Place the squash on the rack, close and seal the lid, and cook on High Pressure for 15 minutes (12 minutes for a small squash, 18 to 20 for a large one).
3. Quick release the pressure. Carefully lift the squash out (it will be very hot) and let it cool for about 5 minutes, then slice it in half lengthwise and scoop out the seeds.
4. Preheat the broiler to high and set a rack about 6 inches below the heat. Use a fork to scrape the squash flesh into strands and put them in a large bowl, leaving a thin layer in the shells so they keep their shape. Set the empty shells on a baking sheet.
5. In a small bowl, stir together the olive oil, Italian seasoning, onion powder, salt and pepper. Pour it over the squash strands, add the Parmesan and half of the Italian blend cheese, and toss until everything is well coated.
6. Pile the cheesy squash back into the shells and sprinkle the remaining Italian blend cheese over the top.
7. Broil for 3 to 5 minutes, until the cheese is melted and golden in spots. Keep a close eye on it, since broilers vary. Serve hot, scooping straight from the shells.

Nutrition

Calories: 235kcalCarbohydrates: 10gProtein: 12gFat: 18gSaturated Fat: 4gPolyunsaturated Fat: 1gMonounsaturated Fat: 6gTrans Fat: 0gCholesterol: 13mgSodium: 254mgPotassium: 144mgFiber: 2gSugar: 3gVitamin A: 235IUVitamin C: 2mgCalcium: 225mgIron: 1mgNet Carbs: 8g

Notes

No Instant Pot? Oven: halve and seed the raw squash, brush the cut sides with a little olive oil, and roast cut side down at 400°F (200°C) for 35 to 45 minutes, until a fork slides in easily. Slow cooker: put the whole pierced squash in a 6-quart or larger slow cooker with ½ cup water and cook on LOW for 5 to 6 hours or HIGH for 3 to 4 hours. Then continue from step 4.

Storing: Keep leftovers in an airtight container in the fridge for up to 4 days. Reheat in the microwave or in a 350°F (175°C) oven until hot.

Nutrition is per serving (a quarter of the recipe) and is an estimate.

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Nutritional information is provided as a courtesy and is my best approximation. Net carbs are calculated as the total grams carbs minus the total grams of fiber.