Description

This Chicken Alfredo Spaghetti Squash Casserole is a comforting, low-carb twist on classic Alfredo pasta. Roasted spaghetti squash replaces traditional noodles, layered with tender cooked chicken, creamy Alfredo sauce, and melted cheeses, then baked to bubbly perfection. Optional vegetables like broccoli and sautéed mushrooms add extra flavor and nutrition, making it a satisfying family-friendly meal that’s both delicious and nutritious.

Ingredients

Scale

Spaghetti Squash

2 medium spaghetti squash (about 3–4 pounds total)
1 tbsp olive oil (for roasting squash)
Salt and pepper (to taste)

Protein and Vegetables

3 cups cooked chicken (shredded or diced, e.g., rotisserie chicken)
1 cup steamed broccoli (optional)
1 cup sautéed mushrooms (optional)

Alfredo Sauce

2 tbsp butter (if making homemade Alfredo)
2 minced garlic cloves (if making homemade Alfredo)
1 cup heavy cream (if making homemade Alfredo)
¾ cup grated Parmesan cheese (for homemade sauce)
Salt and pepper (to taste)
Pinch of nutmeg (optional)
2 cups Alfredo sauce (homemade or store-bought)

Cheese and Seasoning

1 cup mozzarella cheese (shredded)
½ cup Parmesan cheese (grated)
1 tsp garlic powder
1 tsp Italian seasoning

Garnish

Fresh parsley or basil (chopped, optional)

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Instructions

Prepare the Spaghetti Squash: Preheat your oven to 400°F (200°C). Slice each spaghetti squash in half lengthwise and scoop out the seeds with a spoon. Drizzle the cut sides with olive oil, season with salt and pepper, and place cut-side down on a baking sheet. Roast for 30–40 minutes until the flesh is tender and easily pierceable with a fork. Let cool slightly, then use a fork to shred the flesh into spaghetti-like strands. Set aside.
Make the Alfredo Sauce (if homemade): Melt butter in a saucepan over medium heat, sauté minced garlic until fragrant. Stir in heavy cream and simmer gently for 3–4 minutes. Whisk in grated Parmesan cheese until the sauce is smooth and creamy. Season with salt, pepper, and optional nutmeg. Alternatively, use store-bought Alfredo sauce.
Assemble the Casserole: Preheat oven to 375°F (190°C). Grease a 9×13-inch casserole dish. Spread a thin layer of Alfredo sauce on the bottom. Layer half of the spaghetti squash strands, then half of the cooked chicken, followed by half of the Alfredo sauce. Sprinkle some Parmesan cheese on top. Repeat the layers ending with shredded mozzarella cheese on top.
Bake the Casserole: Cover the dish with foil and bake for 20 minutes. Remove the foil and continue baking for an additional 10–15 minutes until the cheese is melted, bubbly, and golden brown.
Serve: Garnish with freshly chopped parsley or basil if desired. Serve warm with a side salad or roasted vegetables for a complete meal.

Notes

Spaghetti squash can be roasted a day ahead to save time when assembling the casserole.
Use rotisserie chicken or leftover cooked chicken for convenience.
Optional vegetables such as steamed broccoli or sautéed mushrooms can be added to the layers for extra flavor and nutrition.
If using store-bought Alfredo sauce, choose a brand you like and adjust seasoning as needed.
Leftovers can be stored in the refrigerator for up to 3 days and reheated in the oven or microwave.
This casserole can be made gluten-free by ensuring the Alfredo sauce and other ingredients do not contain gluten additives.