Spaghetti Squash Alfredo

Ingredients & Substitutions

Here I explain the best ingredients for my spaghetti squash chicken Alfredo recipe, what each one does, and substitution options. For measurements, see the recipe card.

Spaghetti Squash:

• Spaghetti Squash – This is my favorite pasta alternative when I want something cozy and healthy. You can even roast it ahead to save time. For other lighter pasta options, try zucchini noodles (I recommend using the method in my zucchini Alfredo post) or even my homemade keto pasta.
• Seasoning – A pinch of salt brings out the flavor in the squash, and a sprinkle of fresh parsley at the end adds freshness and a pop of color. You don’t need much else, because the sauce will add the flavor!

Chicken:

• Chicken Breast – My personal preference here, but feel free to use boneless chicken thighs if you prefer dark meat.
• Unsalted Butter – I always go for unsalted so I can control the salt in the dish myself. If you only have salted, just reduce any added salt later on.
• Seasonings – I kept it simple with Italian seasoning, garlic powder, sea salt, and black pepper. You can totally swap in your favorite seasoning blend if you like.

Alfredo Sauce:

• Unsalted Butter – For sauteing the garlic, and it gives the sauce that classic richness. You can use olive oil, though.
• Garlic – Fresh minced garlic is best, but you can use a tablespoon of the jarred kind. I’ve done it both ways!
• Heavy Cream – The main ingredient that makes the sauce silky and creamy! It’s sometimes labeled as heavy whipping cream. I don’t recommend swapping in milk or even half and half, because it won’t thicken.
• Grated Parmesan Cheese – I’ve made this spaghetti squash Alfredo with the pre-grated kind and it works, but the flavor and melt are a little better grating it fresh from a block.
• Spices – I add a pinch of nutmeg along with the salt and pepper to give the sauce a little depth. You don’t really notice the nutmeg, but you’d miss it if it wasn’t there.

How To Make Spaghetti Squash Alfredo

I have step-by-step photos here to help you visualize the recipe. For full instructions with amounts and temperatures, see the recipe card.

Roast The Squash:

• Bake it. Poke the spaghetti squash a few times with a paring knife, then roast it on a baking sheet until it’s tender enough to pierce with slight resistance. Flip it once while it cooks. Set it aside to cool, and turn up the oven for the chicken.
• Scoop the strands. Slice the squash in half, scoop out the seeds, and use a fork to pull out the flesh into spaghetti-like strands. Add salt to your taste, keeping in mind the sauce will be salty, too.

Bake The Chicken:

• Season the chicken. Place it in a baking dish and brush with melted butter. Sprinkle both sides with Italian seasoning, garlic powder, salt, and pepper.
• Bake until juicy. I like to pull it out just before it’s fully done, so it finishes as it rests and stays super juicy.
• Let it rest and slice. Cover with foil, let it rest a few minutes, then cut into bite-sized pieces.

Make The Sauce:

• Saute the garlic. While the chicken bakes, melt butter in a large saucepan and sauté the garlic until it smells amazing.
• Pour in the cream. Simmer until it reduces a bit.
• Whisk in the parmesan, then season. Turn the heat to low and slowly whisk in the parmesan until it melts and the sauce is smooth. Stir in the nutmeg, salt, and pepper.

Bring It All Together:

In a large bowl, toss the cooked spaghetti squash with Alfredo sauce. Taste and adjust the seasoning, then add the chicken and toss again. I like to finish my spaghetti squash Alfredo with a sprinkle of fresh parsley.

Serving Ideas

This spaghetti squash Alfredo doesn’t really need much and I often serve it as a light one-dish meal on its own, but you can definitely add some extras. My fave addition is Caesar salad (just skip the chicken) or antipasto salad.

For veggies, sauteed broccoli or roasted broccolini work really well here. And if you’re in the mood for something bready, my cheesy cauliflower breadsticks pair nicely.