Tuesday, September 1, 2026

Creamy Chicken Spaghetti Casserole with Parmesan and Mushrooms

A comforting homemade casserole that turns leftover chicken into a creamy, satisfying family dinner.

Homemade creamy chicken spaghetti casserole with shredded chicken, mushrooms, and Parmesan sauce in a rustic baking dish.

Some of the best family recipes come from knowing how to make something delicious with what you already have. This creamy chicken spaghetti is one of those recipes.

When we had leftover chicken—which wasn't often—my mom would make this dish. Sometimes she would cook a whole chicken and divide the meat in half. She would shred one half and freeze it in a bag to use later, while using the other half to make this comforting chicken spaghetti.

Tender spaghetti and shredded chicken are tossed in a creamy Parmesan sauce with mushrooms and onions, then topped with crispy breadcrumbs or crushed stuffing mix and baked until hot, bubbly, and golden brown.

It's an old-fashioned, practical family recipe that turns leftover chicken into a hearty meal the whole family can enjoy.

Ingredients:  

12 oz spaghetti
1/4 c. butter
1 onion, chopped
1 can mushrooms, undrained
1/4 c.  flour
2 c. chicken broth
1 c. heavy cream or evaporated milk
1/2 tsp. garlic powder
1/2 tsp. onion powder
1 c. Parmesan cheese
Salt & pepper to taste
2 c. cooked, shredded chicken

Directions:

Preheat oven to 350°F. 

Bring a large pot of generously salted water to a rolling boil. Add the spaghetti and cook according to the package directions until just tender, or al dente. Drain well and set aside.

In a cast-iron Dutch oven, over medium heat, melt the butter. Add the chopped onion and cook until tender and translucent, about 4–5 minutes.

Sprinkle the flour over the onions and stir well. Cook for 1–2 minutes, stirring constantly, to cook out the raw flour taste.

Slowly whisk in the undrained mushrooms, chicken broth, and heavy cream or evaporated milk. Continue whisking until the sauce is smooth and thickened.

Stir in the garlic powder, onion powder, and Parmesan cheese. Season with salt and black pepper to taste. Continue stirring until the cheese has melted, and the sauce is smooth and creamy.

Add the cooked spaghetti and shredded chicken to the sauce. Toss gently until the spaghetti and chicken are evenly coated.

You can leave the chicken spaghetti in the cast-iron Dutch oven or a skillet that has a tight-fitting lid.  Or transfer the mixture to a lightly greased 9×13-inch baking dish.

Bake covered for 25–30 minutes, or until the casserole is hot, bubbly.

Allow the chicken spaghetti to rest for about 5 minutes before serving.

Tips for Best Success:

  • Don't overcook the spaghetti. Cook it just until al dente because it will continue cooking while the casserole bakes.
  • Drain the pasta well. Excess water can thin the creamy sauce.
  • Add the flour before the liquids. Cooking the flour with the butter and onions for a minute or two helps prevent a raw flour taste.
  • Whisk the sauce gradually. Slowly adding the broth and cream helps create a smooth, creamy sauce.
  • Use freshly grated Parmesan when possible. It melts more smoothly and gives the sauce a richer flavor.
  • Don't skip the resting time. Letting the casserole sit for about 5 minutes allows the sauce to settle slightly and makes it easier to serve.
  • Watch the salt. The chicken broth, and Parmesan cheese, can all contain salt, so taste the sauce before adding too much additional salt.

Variations and Substitutions:

  • Chicken: Rotisserie chicken works wonderfully, or use leftover baked, roasted, or boiled chicken.
  • Mushrooms: If your family doesn't care for mushrooms, simply leave them out.
    Milk: Evaporated milk makes a good substitute for heavy cream and was commonly used in old-fashioned family recipes.
    Cheese: Try replacing part of the Parmesan with shredded mozzarella, cheddar, or Monterey Jack for a different flavor.
  • Topping: Breadcrumbs give you a simple crispy topping, while crushed stuffing mix adds extra seasoning and a nostalgic flavor. Mix the breadcrumbs or crushed stuffing with 2 tablespoons olive oil.
  • Vegetables: Add peas, broccoli, or chopped cooked carrots if you'd like to include more vegetables.
  • Seasoning: A little dried parsley or Italian seasoning can be added for extra flavor.

Serving Suggestions:

Serve this creamy chicken spaghetti with a simple green salad, steamed green beans, roasted vegetables, or peas.

For a comforting family-style dinner, add warm garlic bread, homemade dinner rolls, or crusty bread for soaking up the creamy sauce.

How to Store:

  • Refrigerator: Allow leftovers to cool and place them in an airtight container. Refrigerate for up to 3–4 days.
  • Freezer: This casserole can be frozen. For best results, place cooled leftovers in a freezer-safe container and freeze for up to 2–3 months. Thaw overnight in the refrigerator before reheating.
  • Reheating: Reheat individual portions in the microwave until heated through. For larger portions, cover with foil and warm in a 350°F oven until hot. If the pasta seems dry, add a small splash of chicken broth or milk before reheating.

Frequently Asked Questions:

Can I use rotisserie chicken for this recipe?
Yes. Rotisserie chicken is an easy substitute for leftover cooked chicken. Remove the skin and bones and shred the meat before adding it to the casserole.

Can I make chicken spaghetti ahead of time?

Yes. Assemble the casserole, cover it tightly, and refrigerate it until you're ready to bake. You may need to add a few extra minutes to the baking time if the casserole is cold from the refrigerator.

Can I use evaporated milk instead of heavy cream?

Absolutely. Evaporated milk works very well and gives the sauce a creamy texture without being quite as rich as heavy cream.

Can I leave out the mushrooms?

Yes. If mushrooms aren't a favorite in your family, you can leave them out without making any other changes.

Can I use a different type of pasta?
Yes. Spaghetti is traditional for this recipe, but linguine, fettuccine, or another long pasta can also be used.

Why did my chicken spaghetti turn out dry?

The pasta may have absorbed more sauce than expected, or the spaghetti may have been overcooked before baking. Be sure to cook the pasta only to al dente and make sure the sauce is creamy before combining everything.

Can I use crushed stuffing mix instead of breadcrumbs?

Yes. Crushed stuffing mix makes a particularly flavorful and crispy topping and is a great choice for this old-fashioned chicken spaghetti.