If you’re looking for a low-carb, healthy twist on a comforting pasta dish, this Amazing Cheesy Chicken Spaghetti Squash Casserole is your new go-to dinner. Packed with tender chicken, roasted red peppers, creamy cheese, and fresh pesto, it transforms spaghetti squash into a cheesy, flavorful casserole that everyone will love. It’s a meal that feels indulgent yet is surprisingly light, perfect for weeknights or family gatherings.
Why You’ll Love This Amazing Cheesy Chicken Spaghetti Squash Casserole
This casserole is a winner for anyone who loves comfort food without the heavy carbs. Here’s why it’s so special:
- Low-carb “pasta” alternative: Spaghetti squash provides the familiar texture of noodles without the extra calories or carbs.
- Cheesy and flavorful: A blend of mozzarella, Parmesan, and pesto ensures every bite is rich and satisfying.
- Healthy protein boost: Tender chicken makes this dish filling and nutritionally balanced.
- Quick and versatile: While it looks gourmet, it’s simple enough for a weekday meal.
- Beautiful presentation: Baking the mixture in the spaghetti squash shells creates a visually stunning dish.
Ingredients for Amazing Cheesy Chicken Spaghetti Squash Casserole
For the Casserole
- 1 medium spaghetti squash, halved and seeded
- 2 cups cooked chicken, diced or shredded
- 1 cup roasted red peppers, chopped
- 1/2 cup pesto (store-bought or homemade)
- 1 cup shredded mozzarella cheese
- 1/2 cup grated Parmesan cheese
- 2 tablespoons fresh basil, chopped
- 2 tablespoons fresh parsley, chopped
- Salt and pepper, to taste
- 1 tablespoon olive oil
Optional Garnish
- 2 tablespoons toasted pine nuts
- Extra fresh basil leaves
Ingredient Notes
- Chicken: Use leftover rotisserie chicken for a shortcut or poach chicken breasts for fresh flavor.
- Pesto: Can substitute with sun-dried tomato pesto or a small amount of basil pesto blended with olive oil.
- Cheese: For a lower-fat version, use part-skim mozzarella and reduce Parmesan slightly.
- Roasted Red Peppers: Jarred roasted red peppers work perfectly; just drain well.
- Vegan/Family-Friendly Swap: Replace chicken with tofu or tempeh, and use vegan cheese if needed.
Step-by-Step Instructions
Step 1 – Roast the Spaghetti Squash
- Preheat oven to 400°F (200°C).
- Drizzle squash halves with olive oil and season with salt and pepper.
- Place cut-side down on a baking sheet and roast for 35–40 minutes until tender.
- Once cool enough to handle, use a fork to scrape the flesh into strands.
Step 2 – Prepare the Chicken
- Dice or shred the cooked chicken.
- Toss chicken with 1/4 cup pesto, a pinch of salt, and pepper.
- Set aside for assembly.
Step 3 – Mix the Filling
- In a large bowl, combine spaghetti squash strands, pesto-coated chicken, chopped roasted red peppers, Parmesan cheese, and fresh herbs.
- Taste and adjust seasoning if necessary.
Step 4 – Assemble the Casserole
- Preheat broiler to medium-high.
- Spoon the mixture back into the squash shells or into a greased casserole dish.
- Sprinkle the mozzarella cheese evenly over the top.
Step 5 – Bake
- Broil for 3–5 minutes, until the cheese is melted and lightly golden.
- Remove from oven and let cool slightly.
Step 6 – Serve
- Garnish with toasted pine nuts and extra fresh basil leaves.
- Serve warm for the best flavor and texture.
Pro Tips for Success
- Don’t overcook the squash: It should be tender but still hold its shape.
- Mix gently: Avoid smashing the squash too much; strands give the casserole a pasta-like texture.
- Use high-quality pesto: Fresh or jarred, the flavor of the pesto really shines in this dish.
- Cheese topping: Broil at the end for a melty, golden top rather than baking too long.
- Make ahead: Assemble ahead of time and refrigerate; broil just before serving.
- Add more veggies: Spinach, zucchini, or mushrooms work beautifully in this casserole.
Flavor Variations
- Mediterranean: Add artichoke hearts, kalamata olives, and feta cheese.
- Spicy: Stir in red pepper flakes or diced jalapeños to the filling.
- Herb-Infused: Mix in thyme or oregano for an earthy, Italian twist.
- Creamy Garlic: Add 1/4 cup cream cheese to the filling for extra richness.
- Sun-Dried Tomato: Swap roasted red peppers for chopped sun-dried tomatoes for tangy sweetness.
Serving Suggestions
- Serve with a side salad or roasted vegetables for a balanced meal.
- Pairs well with a light vinaigrette to cut through the richness of the cheese.
- Enjoy with a slice of crusty bread if you’re not counting carbs.
Storage and Freezing Instructions
- Refrigerator: Store leftover casserole in an airtight container for up to 4 days.
- Freezer: Freeze individual portions in freezer-safe containers for up to 2 months.
- Reheating: Bake at 350°F (175°C) for 15–20 minutes or microwave until warmed through.
Nutrition Facts (Per Serving, 1/4 recipe)
| Nutrient | Amount |
|---|---|
| Calories | 310 |
| Protein | 28g |
| Carbohydrates | 12g |
| Fat | 18g |
| Fiber | 3g |
| Sodium | 520mg |
FAQ About Amazing Cheesy Chicken Spaghetti Squash Casserole
Can I make this casserole dairy-free?
Yes! Use vegan cheese alternatives and skip the Parmesan. Nutritional yeast can also add cheesy flavor.
Can I use raw chicken?
Yes, but cook it first in a skillet or oven until fully cooked before adding to the squash strands.
How do I prevent the squash from being watery?
Scrape the strands gently and let the squash cool slightly. If needed, drain excess liquid before mixing.
Can I prepare this ahead of time?
Absolutely! Mix the filling and store in the fridge; broil cheese topping just before serving.
What if I don’t have roasted red peppers?
You can substitute with roasted tomatoes, sun-dried tomatoes, or even diced bell peppers.
Amazing Cheesy Chicken Spaghetti Squash Casserole
A low-carb, comforting casserole made with spaghetti squash, tender chicken, roasted red peppers, and a rich blend of cheeses and pesto. This healthy yet indulgent dish is perfect for weeknight dinners or family meals.
Equipment
- baking sheet
- large mixing bowl
- knife
- cutting board
- oven
Ingredients
- 1 medium spaghetti squash, halved and seeded
- 2 cups cooked chicken, diced or shredded
- 1 cup roasted red peppers, chopped
- 0.5 cup pesto
- 1 cup shredded mozzarella cheese
- 0.5 cup grated Parmesan cheese
- 2 tbsp fresh basil, chopped
- 2 tbsp fresh parsley, chopped
- salt and pepper to taste
- 1 tbsp olive oil
- 2 tbsp toasted pine nuts (optional)
- fresh basil leaves for garnish (optional)
Instructions
- Preheat oven to 400°F. Drizzle spaghetti squash with olive oil, season with salt and pepper, and roast cut-side down for 35–40 minutes. Scrape into strands once cooled.
- Dice or shred cooked chicken and toss with 1/4 cup pesto, salt, and pepper.
- In a large bowl, combine squash strands, chicken, roasted red peppers, Parmesan cheese, herbs, and remaining pesto. Mix gently.
- Preheat broiler. Transfer mixture into squash shells or a greased baking dish and top with mozzarella cheese.
- Broil for 3–5 minutes until cheese is melted and golden. Remove and let cool slightly.
- Garnish with toasted pine nuts and fresh basil, then serve warm.
Notes
Use rotisserie chicken for convenience and high-quality pesto for best flavor. To reduce moisture, drain spaghetti squash before mixing. For dairy-free, use vegan cheese alternatives. Assemble ahead and broil just before serving.
Nutrition
Calories: 310kcalCarbohydrates: 12gProtein: 28gFat: 18gSaturated Fat: 7gPolyunsaturated Fat: 2gMonounsaturated Fat: 7gCholesterol: 75mgSodium: 520mgPotassium: 450mgFiber: 3gSugar: 4gVitamin A: 2500IUVitamin C: 35mgCalcium: 250mgIron: 2mg
Tried this recipe?Let us know how it was!
Final Thoughts
This Amazing Cheesy Chicken Spaghetti Squash Casserole is a perfect blend of comfort and health. It’s cheesy, flavorful, and packed with protein, yet it remains low-carb and vegetable-rich. Whether for a family dinner, meal prep, or a special occasion, this casserole delivers both flavor and presentation. With endless variations and easy swaps, it’s a recipe you’ll return to again and again.