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This Spaghetti Squash Alfredo with Chicken and Caramelized Onions is hearty comfort food made healthy and nutritious. Perfectly roasted spaghetti squash and tender bites of chicken smothered in a creamy and flavorful, healthy, homemade Alfredo sauce.
Healthier Chicken Alfredo Recipe
Let me just tell you, this Spaghetti Squash Alfredo is not your ordinary Alfredo. But in the best way. It’s creamy and delicious, hearty and satisfying, but also healthy. Yep. This recipe is veggie-packed, loaded with juicy chicken, and made with the best creamy Alfredo sauce.
Oh, and it takes just 15 minutes to prep!
Ingredients Needed for Spaghetti Squash Alfredo
- Spaghetti Squash: You can roast the spaghetti squash in the instant pot or cook it in the instant pot.
- Onion: Caramelized onions make the perfect sweet audition to this chicken Alfredo recipe.
- Butter: You’ll need a little bit of butter to caramelize the onions and a little bit to sauté the garlic. I use grass-fed.
- Garlic: Use freshly minced garlic for the best garlicky flavor.
- Chicken Breast: Use boneless, skinless chicken breast cut into cubes for quicker cooking.
- Mayonnaise: You can use store-bought mayo or make your own paleo mayo.
- Milk: I use almond milk, but whatever milk you have on hand will work.
- Seasonings: We’re spicing up our sauce with a simple combination of garlic powder, onion powder, salt, black pepper, and red pepper flakes.
- Parmesan Cheese: Melting parmesan into the sauce is what gives it that classic Alfredo flavor.
- Fresh Parsley: For garnish!
Can Spaghetti Squash Be Used Instead of Pasta?
Yes! Spaghetti squash is the perfect pasta substitute. It’s fresh, healthy, and light, but can be served any way you’d serve regular pasta…like in chicken Alfredo!
Okay, let’s get to the recipe!
How to Cook Spaghetti Squash
You can easily cook spaghetti squash either in the oven or in the instant pot. I usually roast it in the oven for this recipe, but you can check out my full article on how to cook spaghetti squash for instant pot instructions and more tips and tricks!
How to Make Spaghetti Squash Alfredo
This simple and healthy chicken Alfredo recipe requires just 15 minutes of prep time. Here’s a quick summary of the recipe. Scroll to the recipe card below for the full instructions and ingredient amounts!
- Roast the squash: Slice the spaghetti squash in half lengthwise and scrape out the seeds. Drizzle the top with olive oil, then lay face down on a baking sheet. Roast until fork-tender.
- Caramelize the onions: In a skillet, heat butter, then add in onions. Sauté until golden and caramelized.
- Sear the chicken: In a skillet, heat butter and sauté garlic. Season the chicken with salt and pepper, then add into the skillet and cook on each side until no pink remains.
- Make the sauce: To the pan with the chicken, combine mayo, milk, and spices. Add in the onions and squash, toss to combine, then add the cheese.
- Garnish and serve: You can serve your chicken Alfredo in dishes or just place it back into the spaghetti squash “boat” for easy serving. Finish it off with a sprinkle of fresh parsley and dig in!
How Do You Get Alfredo to Stay Creamy?
There are a few ways you can make sure your Alfredo sauce comes out perfectly creamy! Here are a couple tips:
- Use full-fat mayo. The mayonnaise is what makes the sauce so rich and creamy. Lighter mayonnaise doesn’t achieve quite the same texture. Don’t way mayo? Substitute Cashew Cream!
- Cook on medium-low heat. Lower heat prevents clumps from forming.
- Shred your own cheese. Pre-shredded cheeses contain an anti-caking agent that can cause a gritty texture. Use freshly shredded for the creamiest texture.
- Add the cheese slowly. And whisk constantly to make sure it’s melting smoothly.
Tips and Notes
- Cut the squash carefully! You’ll need a sharp knife and a little elbow grease to slice the squash in half. Just be careful with it!
- Cube the chicken. Cutting the chicken into smaller pieces ensures it cooks more quickly and that it incorporates easily into the spaghetti squash Alfredo.
- Check the texture of the squash. It should be fork-tender so the “spaghetti” can be easily removed before you take it out of the oven.
- Add other veggies. Feel free to mix in other veggies to bulk your meal up. You can sauté them with the onion! Try bell pepper, zucchini, broccoli, you name it.
- Use another meat. You can totally swap the chicken breast out for steak, ground beef, turkey, shrimp, etc. Just make sure you cook it properly!
- Make it vegetarian. Simply leave the chicken out or swap it out for chickpeas.
This chicken Alfredo is delicious all on its own, but it’s also great paired with a side of:
- Gluten-Free Garlic Bread
- Air Fryer Broccoli
- Garlicky Blistered Green Beans
- …or any of your favorite side dishes!
How to Store
Leftover spaghetti squash Alfredo will last in an airtight container in the fridge for 3-5 days. I don’t recommend freezing it because the texture of the squash and the sauce will be affected.
To reheat, warm in the microwave or on low on the stove with a splash of milk to moisten.
Looking for More Spaghetti Squash Recipes?
- Spaghetti Squash Primavera
- Spaghetti Squash Italian Casserole
- Spaghetti Squash Pad Thai
- Fajita Spaghetti Squash Bake
- Chicken Enchilada Spaghetti Squash Casserole
Spaghetti Squash Alfredo with Chicken and Caramelized Onions
- 1 spaghetti squash roasted
- 1 large onion sliced
- 2 tablespoons butter
- 2 garlic cloves minced
- 1 pound boneless chicken breasts cubed
- 1/2 cup mayo homemade or store-bought
- 2 tablespoons unsweetened almond milk
- 1/2 teaspoon garlic powder
- 1/2 teaspoon onion powder
- Pinch salt more to taste
- Pinch black pepper more to taste
- Pinch red pepper flakes more to taste
- 1/2 cup fresh parmesan cheese
- Chopped fresh parsley for garnish
- Preheat oven to 400°F.
- Slice spaghetti squash in half and scrape out seeds. Drizzle with extra-virgin olive oil and place face down on a lined baking sheet and roast for 30 minutes or until fork tender.
- Make caramelized onions: In a skillet heat 1 tablespoon of grass-fed butter with onions. Sauté on medium-low heat until onions begin to caramelize and brown, but not burn. Yields about 1 cup of caramelized onions.
- In a skillet over medium heat, heat butter and sauté garlic for 1 minute.
- Season chicken with salt and pepper and add into the skillet. Let cook for 6 minutes, or until no pink remains, flipping halfway through.
- Add in mayo, almond milk, and spices. Mix to combine.
- Add in caramelized onions and spaghetti squash. Toss to combine. Add the parmesan cheese and adjust spices as desired.
- Garnish with fresh parsley and serve hot.
- Leftover spaghetti squash Alfredo will last in an airtight container in the fridge for 3-5 days. I don't recommend freezing it because the texture of the squash and the sauce will be affected.
- To reheat, warm in the microwave or on low on the stove with a splash of milk to moisten.