This homemade Chicken Spaghetti Casserole is adapted from the Pioneer Woman's recipe and uses a shredded Costco rotisserie chicken to make it easy to throw together on a weeknight. Perfectly al dente pasta combine with a made-from-scratch cream of mushroom soup sauce with chopped green pepper, pimentos, diced onion, and a generous amount of shredded cheddar cheese. This is a family favorite!
We love a good pasta dinner! Some of our other favorites are Chicken Fettuccine Alfredo, 30 Minute Cajun Pasta with Sausage and Peppers, and Homemade Hamburger Helper Cheeseburger Pasta Skillet (with Video!)
I don't know where chicken spaghetti came from in the first place, but I know I first saw it in the Pioneer Woman's cookbook years ago. This chicken spaghetti casserole recipe, along with her chicken pot pie recipe, were my two favorites from that book.
I love a good casserole, and this isn't the first spaghetti casserole I've posted on the blog. My other favorite is creatively called "spaghetti casserole" but really I think of it as a poor man's lasagna, made with cottage cheese and spaghetti instead of ricotta and lasagna noodles. Another favorite dinner casserole that you really should try is my cheesy chicken broccoli and rice casserole.
The biggest change I made to the Pioneer Woman's original chicken spaghetti recipe was to swap out the cream of mushroom soup in favor of a homemade version. It takes very little additional time, tastes WAY better, and is better for you anyway.
Chicken Spaghetti is one of the best make ahead meals
I love chicken spaghetti casserole because it's such an easy recipe to make ahead and stick in the fridge or freezer until you need it.
All it takes is about 15 minutes of chopping veggies, making the mushroom sauce, and mixing the casserole components together, and then it bakes in the oven until hot and bubbly. The beauty of it is that you can make the casserole a day or two in advance and it tastes just as good when you finally decide to bake it as when it was first made.
Chicken spaghetti also makes a great freezer meal! You can freeze this chicken spaghetti recipe for 2 months, then thaw in the fridge overnight. It's one of those recipes that I keep in my back pocket for taking to friends who have had babies or are dealing with family health issues because it can be ready and on hand whenever they need it.
It's honestly not a bad idea to double the recipe and make two casseroles as long as you are making one. Especially since you only need half of a green pepper and half of an onion to make one casserole. Keep one in the freezer to have on hand for a busy weeknight or give one away to a friend in need!
Ingredients in Chicken Spaghetti Casserole
- cooked chicken
- spaghetti noodles
- diced mushrooms
- chicken broth
- green bell pepper
- pimentos (a type of jarred pepper that is sweet and mild but ½ of a chopped red bell pepper will also work)
- yellow onion
- sharp cheddar cheese
How to Make Chicken Spaghetti
- Cook some chicken or buy a rotisserie chicken: I've used leftover grilled chicken, roasted chicken, poached chicken, and those rotisserie chickens that we all love. Honestly, I think I prefer the rotisserie chicken in this recipe! It just makes things so much easier and I almost always grab one anytime I'm at Costco anyway since they are so convenient and priced reasonably. Shred or cube the chicken. I usually get around 3 to 4 cups worth off one rotisserie chicken.
- Cook the spaghetti: I took a note from the Pioneer Woman's book where she cooks her spaghetti noodles in some of the broth that is leftover from cooking a cut-up fryer chicken. Since I use a rotisserie chicken, I usually just add about 3 tablespoons of "Better Than Bouillon" chicken base to the pot of water that I use to boil the spaghetti in. It's optional and you could just cook the pasta in regular salted water, but I do think it adds flavor.
- Make the Cream of Mushroom Soup sauce: Just melt a little butter in a large pan, then add diced mushrooms and cook until the mushrooms have released most of their liquid, about 5 minutes. Then add a little more butter and sprinkle some flour over the sauteed mushrooms, stirring to cook it for about 30 seconds. Add some liquid in the form of chicken broth and milk and season with salt and pepper, whisking and cooking over a simmer until the sauce thickens, about 5 minutes.
- Combine all of the casserole ingredients in a big bowl: Save about ¾ cup of shredded cheese to sprinkle over the top, but otherwise, the shredded chicken, cooked and drained spaghetti, and chopped veggies get thrown into a big bowl and stirred together with the homemade cream of mushroom soup. Then transfer it to a large baking dish and sprinkle with the remaining cheese. I find that the pasta will often look a little dry at this point, so I will pour 1 extra up of chicken broth over the casserole once it is in the pan.
- Bake for 40 minutes until hot and bubbly!
More Recipes for Pasta Lovers
- One Pot Bruschetta Chicken Pasta
- Homemade Hamburger Helper Cheeseburger Pasta Skillet
- Angel Hair Pasta with Shrimp, Tomatoes and Fresh Basil
- BLT Pasta Salad
- Roasted Red Pepper Sauce
- White Chicken Spinach Lasagna
- The Best Spaghetti and Meatballs Recipe
Did you make this recipe?
Let me know what you thought with a comment and rating below. You can also take a picture and tag me on Instagram @houseofnasheats or share it on the Pinterest pin so I can see.
Chicken Spaghetti Casserole
- 4 Tablespoons butter divided
- 8 ounces cremini mushrooms diced
- 3 Tablespoons all-purpose flour
- 2 cups chicken broth
- 1 cup milk
- ¼ teaspoon salt
- ¼ teaspoon black pepper
- 1 pound spaghetti broken into 2-inch pieces
- 3 Tablespoons chicken bouillon
- 3-4 cups cooked chicken shredded
- 1 small yellow onion chopped
- ½ green bell pepper chopped
- 4 ounces pimentos, drained
- 2 ½ cups grated cheddar cheese divided
- 1 teaspoon seasoned salt
- ⅛ to ¼ teaspoon cayenne pepper
- 1 cup chicken broth
- Preheat oven to 350 degrees F.
- Melt 1 tablespoon of butter in a large sauce pan, then add the diced mushrooms and cook for 3-5 minutes over medium-high heat, stirring frequently, until most of the liquid released from the mushrooms cooks off.
- Add remaining butter and let melt, then sprinkle with the flour and stir and cook for 30 seconds.
- Whisk in the chicken broth and milk, about ½ cup at a time, until combined. Stir in salt and pepper, then simmer for 3-5 minutes until slightly thickened. Remove sauce from heat and set aside.
- Fill a large pot with water and bring to a boil. Add the spaghetti and season the water with about 1 tablespoon of salt. I also like to add 3-4 tablespoons of chicken-flavored Better Than Bouillon to the water to flavor the spaghetti noodles while they cook. Cook according to package directions until al dente, then drain.
- In a large bowl, combine the cooked spaghetti noodles, chicken, onion, bell pepper, pimentos, 1 ¾ cups cheese, seasoned salt, and cayenne pepper. Pour the sauce over everything and stir to combine. Transfer to a 9x13-inch baking dish.
- Pour remaining 1 cup chicken broth over the pasta, then sprinkle with the remaining ¾ cup cheese. Bake for 35 to 40 minutes until the cheese is melted and the casserole is hot and bubbly.