Keto Chicken Alfredo Casserole Recipe

Spaghetti squash, pan-seared chicken breast, and a cream sauce built from heavy cream, cream cheese, and Parmesan go into this keto chicken Alfredo casserole. It bakes at 350°F under a mozzarella and Parmesan topping and makes 10 servings in about 1 hour 15 minutes.

Spaghetti squash replaces pasta here, which is what keeps it low-carb without giving up the creamy Alfredo flavor. The sauce needs no flour or roux. Butter, heavy cream, cream cheese, and Parmesan melt together over medium-low heat into a thick coating that wraps around every strand.

After the squash bakes and cools, the strands need to rest a few minutes first. Spaghetti squash releases water as it cools, and that liquid thins the Alfredo sauce during baking and makes the casserole loose. Blotting the strands dry with paper towels before mixing is what keeps the sauce thick when the dish comes out.

Keto Chicken Alfredo Casserole Recipe

Recipe by Emily MitchellCourse: Uncategorized

Servings

10

servings

Prep time

15

This step is where restaurants pull ahead.

61 recipes with the full professional method. The details that change everything.

Get it on Amazon · £9.99

minutes

Cooking time

1

hour 

Calories

325

kcal

The squash bakes at 400°F first, then the assembled casserole drops to 350°F for the final bake. Eleven ingredients, a 13×9-inch baking dish, 1 hour 15 minutes, serves 10.

Ingredients

• Chicken

• 1½ lbs boneless skinless chicken breasts, cut into 1-inch cubes

• 2 tablespoons unsalted butter

• 1 tablespoon olive oil

• 1 teaspoon salt-free Italian seasoning

• ½ teaspoon sea salt

• ¼ teaspoon black pepper

• Keto Alfredo Sauce

• 3 cups heavy whipping cream

• 2 oz cream cheese, softened

• 1 cup shredded Parmesan cheese

• ½ teaspoon garlic powder

• ½ teaspoon onion powder

• ⅛ teaspoon nutmeg

• 1 teaspoon sea salt

• 1 teaspoon black pepper

• Casserole Base

• 1 large spaghetti squash (about 3.5 lbs)

• Cheese Topping

• 2 cups shredded mozzarella cheese

• 1 cup shredded Parmesan cheese

• Garnish

• ¼ cup fresh parsley, chopped

Directions

• Preheat oven to 400°F. Line a large baking sheet with parchment paper.
• Cut the spaghetti squash in half lengthwise and remove the seeds. Place cut side down on the prepared baking sheet. Bake for 45 to 50 minutes until a knife inserts easily.
• Let the squash cool for 15 minutes. Scrape the flesh into strands using a fork. Let the strands rest a few minutes, then blot with paper towels to remove excess moisture. Set aside.
• Season the chicken with ½ teaspoon salt, ¼ teaspoon black pepper, and Italian seasoning. In a large skillet over medium-high heat, melt the 2 tablespoons of butter with the olive oil. Cook the chicken until golden and cooked through, reaching an internal temperature of 165°F. Set aside.
• In a small saucepan over medium-low heat, melt a small knob of butter (see Notes). Add the heavy cream, cream cheese, garlic powder, onion powder, nutmeg, salt, pepper, and Parmesan. Cook for 5 to 7 minutes, stirring, until the cheese melts and the sauce thickens. Set aside.
• Reduce the oven temperature to 350°F. Grease a 13×9-inch baking dish.
• In a large bowl, combine the spaghetti squash strands, cooked chicken, and Alfredo sauce. Toss until everything is evenly coated. Transfer to the prepared baking dish and spread evenly.
• Combine the topping mozzarella and Parmesan in a small bowl. Scatter evenly over the casserole.
• Bake for 35 to 45 minutes until golden brown and bubbling across the top. If the cheese needs more color at 45 minutes, broil for 3 to 5 minutes while watching closely.
• Garnish with fresh parsley and serve warm.

FAQs

Why does spaghetti squash make the casserole watery?

Spaghetti squash holds water inside its cells, and that moisture releases as the cooked strands cool. Adding them straight to the bowl without resting first lets that liquid mix into the sauce and thin it before baking. Resting the strands a few minutes and blotting with paper towels first removes enough moisture to keep the sauce creamy.

Can I use rotisserie chicken instead?

Yes, rotisserie chicken works well here and cuts the prep time significantly. Shred or chop the cooked chicken and fold it straight into the spaghetti squash and Alfredo sauce without any stovetop cooking first. Use a plain or lightly seasoned bird so the seasoning does not compete with the Alfredo sauce.

Can I add broccoli or spinach?

Both work well in this casserole without changing the bake time. Use lightly steamed broccoli florets or fresh baby spinach, and make sure both are drained and dried well before mixing in. Extra moisture from frozen or undercooked vegetables will loosen the sauce the same way wet squash strands do.

How do I know when the casserole is done?

The cheese topping should be deep golden brown across the entire surface with no pale patches. The center should feel set when pressed gently and the edges should be bubbling. If the top still needs color at 45 minutes, broil for 3 to 5 minutes while watching closely so the cheese does not burn.

What pairs well at a low-carb dinner table?

A cream-based bake with a different flavor profile makes the best companion here. The spinach artichoke chicken bake brings artichokes and mozzarella into the spread, which contrasts the Parmesan Alfredo sauce without repeating it. Both bake at 350°F and can finish around the same time.

What if I want a non-keto version of this dish?

If you are not following keto, regular penne works in place of spaghetti squash for a chicken Alfredo pasta bake. Creamy chicken penne pasta uses the same Alfredo-style sauce but comes together in 30 minutes on the stovetop with no oven time. The two recipes share the same flavor with completely different textures and timelines.