Last updated on December 29, 2025

One cold evening, I found myself rummaging through my kitchen, hoping to create something cozy and comforting. That’s when I stumbled upon a large spaghetti squash that had been waiting for its moment. It reminded me of times spent in my grandmother’s kitchen, where we often turned fresh vegetables into hearty meals. I decided to combine that squash with some chicken and cheese, intuitive flavors from my childhood. However, as I prepared to make the Cheesy Chicken Spaghetti Squash Casserole for the first time, I felt a familiar wave of apprehension. Would I overcook the squash? Could I mess up the chicken? If you’ve ever felt that twinge of fear when trying a new recipe, know this: my step-by-step guide will make preparing this dish simple, stress-free, and absolutely delightful—even on your very first attempt.

Why I Love This Recipe of Cheesy Chicken Spaghetti Squash Casserole

This Cheesy Chicken Spaghetti Squash Casserole is special to me because it embraces the comfort of home-cooked meals while offering a healthy twist. Using spaghetti squash instead of traditional pasta makes it a wonderful guilt-free option. I appreciate how versatile it is; you can customize it based on what you have in your pantry or to suit different dietary needs. It’s not just a dish; it’s a warm hug on a plate, perfect for sharing with family or enjoying on a cozy night in.

More than that, this recipe is beginner-friendly, with straightforward steps that won’t overwhelm you even if you’re still getting familiar with your kitchen. It’s practical, comforting, and offers a classic flavor profile that caters to both kids and adults alike. You’ll feel like a culinary genius when you pull this bubbling, cheesy goodness out of the oven!

Ingredients You’ll Need for Cheesy Chicken Spaghetti Squash Casserole

When it comes to making my Cheesy Chicken Spaghetti Squash Casserole, you only need a handful of simple ingredients that you might already have at home. Here’s a breakdown of what you’ll need:

Essentials

1 large spaghetti squash: This is the star of the show, providing that wonderful noodle-like texture.
2-3 large chicken breasts (about 1.25 pounds): These will add protein and heartiness to the dish.
1 Tablespoon Italian seasoning: A blend of herbs that will infuse the dish with classic Italian flavors.
1/2 teaspoon salt: Essential for enhancing all the flavors.
1 medium green bell pepper, diced: Adds a nice crunch and sweetness.
6 ounces diced tomatoes (drained, about 2/3 cup): For moisture and a pop of flavor.
1 10.5 ounce can cream of mushroom: This gives the casserole a creamy texture and rich taste.
1/4 cup plain Greek yogurt: A healthier alternative to sour cream, adding creaminess without guilt.
1 teaspoon minced garlic: Garlic is essential in elevating the dish’s flavors.
2 cups shredded cheese (divided): A mix of your favorite cheese for melty goodness.
2 Tablespoons chopped fresh basil or chives (optional): While this adds a nice touch, it’s not necessary if you don’t have it on hand.

Optional Add-Ons

The beauty of this casserole is that you can make it your own! Feel free to mix in or top with any of the following:

Spinach or Kale: For added nutrition, you could throw in some spinach or kale.
Different Cheeses: Experiment with mozzarella, cheddar, or even pepper jack for a bit of spice.
Different Vegetables: Swap the green bell pepper with zucchini or carrots.

Substitutions and Shortcuts

For the Chicken: You can use rotisserie chicken for an even quicker preparation. Just shred it and add it to the mix.
Dairy-Free Option: To replace cheese, consider using a cashew cheese or a dairy-free alternative.

When cooking, feel empowered to make adaptations based on your preferences. This recipe is made for tweaking!

How to Make Cheesy Chicken Spaghetti Squash Casserole Step-by-Step

Now, let’s dive into the cooking process! Follow these steps, and you’ll have a delectable casserole in no time.

Step 1: Prepping the Chicken and Spaghetti Squash

Preheat your oven to 400 degrees F. This ensures everything cooks evenly and crisps up nicely.
Carefully cut the spaghetti squash in half lengthwise. Use a sturdy knife, as this can be tricky. Once halved, scoop out the seeds to clear the inside.
Take a large baking pan and fill it with about a 1/4-inch layer of water. Place each spaghetti squash half face down in the pan. This steaming process will help the squash soften evenly.

Step 2: Baking the Chicken and Squash

In a large 9×13-inch casserole dish, place your chicken breasts. Sprinkle Italian seasoning and salt evenly over the top. This will create a flavor-packed chicken base for your casserole.
Now, pop both the baking pan with the squash and the casserole dish with the chicken into the preheated oven. Bake for 45-50 minutes, or until the spaghetti squash is soft and the chicken is fully cooked (the chicken should reach 165 degrees F).

Step 3: Preparing the Rest of the Ingredients

While the squash and chicken are baking, prepare your other ingredients: dice the green bell pepper, drain the diced tomatoes, and measure out the cream of mushroom soup, Greek yogurt, and minced garlic.

Step 4: Assembling the Casserole

Once the squash and chicken are done, remove them from the oven. Let them cool slightly.
Shred or dice the chicken into small pieces. This is where you’ll see your hard work paying off!
Using a fork, scrape the spaghetti squash to remove the ‘noodles’ and transfer the strands into a large bowl.
In that same bowl, combine the scraped squash with the chicken, green bell pepper, drained tomatoes, cream of mushroom soup, Greek yogurt, minced garlic, and half of the shredded cheese. Mix everything nicely until well combined.

Step 5: Baking the Casserole

Transfer this mixture into the casserole dish, smoothing it out evenly.
Top the entire dish with the remaining shredded cheese—don’t skimp on this; it’s where the magic happens!
Reduce the oven’s heat to 350 degrees F and bake for an additional 15-20 minutes or until everything is hot and the cheese has melted beautifully.

Step 6: Adding the Finishing Touches

Once out of the oven, sprinkle with fresh basil or chives if desired. This adds a delightful burst of freshness and color to your dish.

Common Mistakes to Avoid

Even the simplest recipes can have their pitfalls. Here are a few common mistakes to avoid when making Cheesy Chicken Spaghetti Squash Casserole:

Cutting Squash Properly

One of the biggest challenges with spaghetti squash is cutting it properly. Make sure you have a sharp knife and cut firmly down the middle. If you have difficulty, you might microwave the squash for 2-3 minutes to soften it slightly, making it easier to cut.

Undercooking or Overcooking the Chicken

Chicken breasts can easily become dry if overcooked, but undercooked chicken is not safe. Use a meat thermometer to check that your chicken reaches the safe cooking temperature of 165 degrees F.

Not Draining the Diced Tomatoes

Leaving the excess liquid in the diced tomatoes can make your casserole watery. Always drain them thoroughly to keep your casserole creamy but not soupy.

Serving Suggestions for Cheesy Chicken Spaghetti Squash Casserole

This Cheesy Chicken Spaghetti Squash Casserole pairs wonderfully with a variety of sides, and I have a few suggestions to make your meal even more delightful.

With a Green Salad

A fresh green salad is always a fantastic accompaniment. Toss together leafy greens, cherry tomatoes, and a light vinaigrette for a refreshing contrast to the rich casserole.

Bread on the Side

Serve with crusty bread or garlic bread for dipping. The cheesy flavors of the casserole marry well with the crunch of bread.

Pair with Roasted Vegetables

Roasted veggies provide a great complement to the casserole’s flavors. Think about roasting some seasonal vegetables, like zucchini, carrots, or Brussels sprouts, seasoned simply with olive oil, salt, and pepper.

Conclusion

You’ve made it! As you can see, preparing Cheesy Chicken Spaghetti Squash Casserole is easier than it looks. Once you master the steps, you can customize it to fit your family’s tastes or dietary needs. It’s a cozy, classic dish that’s beginner-approved and perfect for weeknight dinners or meal prep.

With just a handful of simple ingredients and a little love, you can create a comforting dish that feels like a warm hug. So roll up your sleeves, and let’s make some memories in the kitchen. Happy cooking!

FAQs About Cheesy Chicken Spaghetti Squash Casserole

What is Cheesy Chicken Spaghetti Squash Casserole? Cheesy Chicken Spaghetti Squash Casserole is a comfort food dish that combines cooked spaghetti squash, chicken, cheese, and a creamy sauce, baked until bubbly and golden.
Is Cheesy Chicken Spaghetti Squash Casserole healthy? Yes! This casserole uses spaghetti squash instead of traditional pasta, lowering the carbs while providing plenty of nutrients.
Can I use leftover chicken for this casserole? Absolutely! Using leftover rotisserie chicken is a great shortcut for this recipe.
How can I customize my Cheesy Chicken Spaghetti Squash Casserole? You can add different vegetables, use various types of cheese, or even include spices that suit your family’s taste preferences.
Can I freeze leftovers of Cheesy Chicken Spaghetti Squash Casserole? Yes, you can freeze portions of the casserole after it’s baked; just make sure to store it in an airtight container. When reheating, do so slowly to retain its texture.

Cheesy Chicken Spaghetti Squash Casserole

Why I Love This Recipe of Cheesy Chicken Spaghetti Squash Casserole