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spaghetti squash in white baking dish coated in cheese.

Chicken Spaghetti Squash Casserole

CHICKEN SPAGHETTI SQUASH CASSEROLE is a low carb riff on the classic chicken spaghetti! Made with shredded chicken, tomatoes & chiles, and a creamy cheese sauce all mixed up with spaghetti squash.

low carb chicken spaghetti squash recipe on white plate.

This time of year is when I am all about the mighty casserole.

I love mixing a bunch of things together and popping them in the oven to bake into a hot, cheesy, bubbly mess of tasty goodness.

It was a struggle to figure out casseroles when we first went low carb, since we often used pasta or rice as the base for our casseroles.

Now we’ve figured out which veggies work best and how to use them!

I took our family’s old favorite, chicken spaghetti, and swapped out the pasta for spaghetti squash and made a keto cheese sauce.

The spaghetti squash is a bit sweet and earthy, which pairs really well with the spice of the tomatoes and green chiles.

How to:

This recipe is a bit involved, as you’ll need to cook the spaghetti squash, then the cheese sauce, then combine everything, and then bake.

That said, it’s all easy to do – just takes a bit of time!

Spaghetti Squash:

Start by cooking your spaghetti squash.

We like to cook ours in the Instant Pot. Instant Pot Spaghetti Squash cooks quickly and easily.

how to cook spaghetti squash in instant pot

You can also halve your squash, scoop out the seeds, and roast for around an hour at 400 degrees.

Scrape the squash out into long strands and place in a large mixing bowl.

I believe you can also buy frozen bags of spaghetti squash strands that you steam in the bag. Those would also work well here, if you want to cut down on prep.

spaghetti squash strands in glass bowl.

Cheese Sauce:

We’re using my keto cheese sauce in this recipe. It’s thick, creamy, and just perfect!

You’ll just add cream, cream cheese, and butter to a small pot and heat until smooth and creamy.

Stir in cheddar and spice until melted.

This is great over steamed veggies too!

smooth and creamy cheese sauce recipe

Assembly:

Add shredded chicken (rotisserie chicken is great here), a can of diced tomatoes and green chiles, garlic, and onion powder to the bowl with the spaghetti squash.

Pour the cheese sauce over the top and give it a good stir.

Transfer this to a 9×13 baking dish and bake for 20 minutes, just to get everything hot and bubbly.

We sprinkle with chives or green onions just before serving.

baked chicken spaghetti squash casserole in white dish.

Serving Suggestions:

This recipe is really a meal by itself, but we always serve casseroles with either a pile of roasted vegetables or a simple green salad.

These roasted green beans or roasted Brussels sprouts and cauliflower are a great option.

If you go the salad route, try it with my keto ranch dressing. It’s the best ranch ever!

cheesy keto spaghetti squash recipe on white plate.

More keto casseroles:

cheesy spaghetti squash recipe in baking dish.

Follow me on social for more recipe ideas & inspiration!

cheesy keto spaghetti squash recipe on white plate.

Chicken Spaghetti Squash Bake

This chicken spaghetti squash casserole is a riff on the classic chicken spaghetti. It's creamy and cheesy with a bit of spice from the diced tomatoes and chiles and sweetness from the spaghetti squash.

Yield 6 servings
Prep Time 30 minutes
Cook Time 1 hour 20 minutes
Total Time 1 hour 50 minutes

Ingredients

  • 1 whole spaghetti squash, about 3 pounds
  • 1 1/4 cups heavy whipping cream
  • 2 ounces cream cheese
  • 2 tablespoons butter
  • 1/2 teaspoon ground mustard
  • 1/2 teaspoon pepper
  • 6 ounces cheddar, shredded
  • 3 ounces mozzarella, shredded
  • 3 cups cooked, shredded chicken
  • 10.5 ounces Ro*Tel, drained
  • 2 cloves garlic, minced
  • 1 teaspoon onion powder
  • Chives, for garnish

Instructions

To cook the spaghetti squash:

  1. To cook in the oven, preheat oven to 400 degrees. Cut the squash in half length-wise and scoop out the seeds with a spoon. Discard the seeds. Drizzle with olive oil and place face down on a baking sheet. Bake for 1 hour or until squash is fork tender.
  2. To cook in the Instant Pot, follow follow these directions..
  3. Once squash is cooked, shred the squash into long spaghetti-like strands by using a fork to scrape the squash widthwise. 
  4. Place the strands of squash in a large mixing bowl.

To make the cheese sauce:

  1. Add the heavy cream, cream cheese, and butter to a medium sauce pan and cook over medium heat until the butter and cream cheese have melted, stirring often.
  2. Whisk in the ground mustard and pepper.
  3. Remove from the heat and whisk in the cheddar and mozzarella until the mixture is smooth and creamy.

To assemble: 

  1. Reduce oven heat to 350 degrees. Spray a 9x13 baking dish with non-stick spray. 
  2. Add the chicken, Ro*Tel, garlic, and onion powder to the mixing bowl with the spaghetti squash.
  3. Pour the cheese sauce over the top and stir gently to coat. 
  4. Pour mixture into the prepared baking dish and bake for 20 minutes or until hot and bubbly. 
  5. Sprinkle with chives before serving. 

Notes

3 pounds of spaghetti squash will yield around 4 cups of spaghetti squash strands.

We didn't measure servings by volume. We just divided evenly into 6 portions, however each serving will be around 1 cup.

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Nutrition Information:

Yield: 6 Serving Size: 1 cup
Amount Per Serving: Calories: 553Total Fat: 42gSaturated Fat: 24gTrans Fat: 1gUnsaturated Fat: 14gCholesterol: 164mgSodium: 435mgCarbohydrates: 12gNet Carbohydrates: 10gFiber: 2gSugar: 6gProtein: 30g

All information and tools presented and written within this site are intended for informational purposes only. This information is provided as a courtesy and there is no guarantee that the information is accurate.

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19 thoughts on “Chicken Spaghetti Squash Casserole”

  1. Haley Goldman

    This is a fantastic recipe. I’ve used it with spaghetti squash, regular spaghetti, and last night I used the cheese sauce in homemade hamburger helper. My kids loved it! Thank you so much for this delicious recipe!

    1. Karly Campbell

      Both the spaghetti squash and tomatoes have carbs. The cheese, cream, and spices do as well, though those are small amounts. It all adds up though.

  2. I’ve been perusing your site for a few months now, trying a handful of recipes. I just tried this one last night and it was a huge hit in my house! I cooked up some chopped bacon and put it out on with the chives to be used as a topping, and it was DEVINE. Thanks for another great, low-carb option!

    1. Karly Campbell

      Oh, I bet the bacon was a great addition! So glad you’re enjoying the recipes. 🙂

  3. Andrea L Behrend

    Does this have a wet slimy texture to it? I have never has spaghetti squash because I thought it would be wet/slimy but I now have to watch my carbs and I am missing spaghetti

  4. Carol Stephens

    When you put it that way, you’re probably right. I’ll have to think about it. Thanks!

  5. Carol Stephens

    This looks wonderful! I can’t wait to try it, but I have to keep my dairy free granddaughter in mind when she is with me. Do you think this would work with a non-dairy keto gravy?

    1. Karly Campbell

      Hi Carol! I think you could probably put anything you like over the spaghetti squash and bake it, if you think the flavors will work well together. Gravy + Rotel + chicken doesn’t sound like a great flavor combo to me, but if it sounds good to you, go for it. 🙂

  6. Jim V Butterfield

    We love spaghetti squash, well she does, i just eat it. Thanks for the twist. Always looking for new ways to spice up Spaghetti squash.

  7. Ok, I had a spaghetti squash that was getting a little long in the tooth…and it was still good! I did use the instant pot and followed your recipe except for 1 thing. I used Serrano peppers in the dish along with the ROTEL. I don’t see a way to leave a photo Looking forward to having it tonight! Thanks!

    1. Karly Campbell

      Hope you loved it, Walter! We’re working on a way for readers to add photos to the next site design in a few months. 🙂

  8. Opened email and SO glad to see this since I’ve been craving it! (Even bought the spaghetti squash during grocery shopping this weekend.) Now I can have it guilt-free. 🙂

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