I knew Chicken Tetrazzini would become a regular in our dinner rotation the first time I made it. That golden, bubbly cheese on top gives way to creamy mushroom sauce coating every strand of spaghetti and tender chicken underneath. The sour cream makes it rich without being heavy. Every forkful is comforting and exactly what you want when dinner needs to satisfy everyone.

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I make this for weeknight family dinners, potlucks, and after the holidays when I need to use up leftover chicken or turkey. It’s perfect for meal prep since you can assemble it ahead and refrigerate until you’re ready to bake. The creamy, cheesy comfort always goes over well with a crowd. Leftovers stay fresh in the fridge for 3 days or freeze for up to 3 months.
Ingredients You’ll Need
You’ll need all the ingredients shown in the photograph below.

How to Make Chicken Tetrazzini with Step-By-Step Instructions
Scroll down for the full recipe card containing a full printable recipe and measurements in both US customary and metric units.
You’ll have the casserole assembled and ready to bake in about 15 minutes.
Preheat and Prep
Preheat your oven to 350°F and lightly grease a 9×13-inch baking dish with cooking spray or butter. I like using this ceramic baking dish because it distributes heat evenly and makes cleanup easier.
Make the Creamy Sauce
In a large mixing bowl, whisk together the cream of mushroom soup, sour cream, melted butter, chicken broth, salt, pepper, and garlic powder until smooth. I reach for my batter bowl for this step since it gives me plenty of room to combine everything without splashing.
The sauce should be thick and creamy with no lumps.
SERIOUSLY GOOD
CASSEROLES
37 EASY RECIPES designed for days when you want one dish to do all the work for you. Expect rich, mouthwatering layers that are just begging to be on your dinner table.
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Includes ad-free recipes like:
∙ Breakfast Casserole
∙ Cheeseburger Casserole
∙ Four Cheese Ravioli Casserole
∙ Chicken Pot Pie Casserole
∙ Sweet Potato Casserole
...and much more!
Combine the Pasta, Chicken, and Peas
Add the cooked thin spaghetti, chopped chicken, and frozen peas to the bowl with the sauce. Stir everything together until every strand of pasta and piece of chicken is coated in the creamy mixture.
The peas will thaw as you mix, adding little pops of color throughout.
Transfer to the Baking Dish
Pour the entire mixture into your prepared baking dish and spread it out evenly with your spatula. Sprinkle the mozzarella, cheddar, and Parmesan cheese over the top in an even layer so every portion gets cheesy and golden.
Bake Until Golden and Bubbly
Cover the dish with aluminum foil and bake for 30 minutes. Remove the foil and continue baking for another 10 to 15 minutes until the cheese is melted, golden, and bubbling around the edges. The top should have some golden brown spots where the cheese has crisped slightly.

Cool and Serve
Let the casserole cool for about 5 minutes before serving, so the sauce thickens slightly and it’s easier to scoop. Snip fresh parsley over the top with herb scissors for a pop of color and freshness.
If you’re taking the casserole to a potluck or party, let it cool for 10 minutes first so it sets up properly. An insulated casserole carrier keeps the dish hot for hours during transport and protects it from spills.

Chicken Tetrazzini
Equipment
Ingredients
- 1 pound cooked chicken chopped
- 1 pound thin spaghetti cooked al dente
- 1 ½ cups shredded mozzarella cheese
- ½ cup shredded cheddar cheese
- 2 tablespoons grated Parmesan cheese
- 2 cups sour cream
- ½ cup unsalted butter melted
- 1 (10 ounces) can cream of mushroom soup
- ½ cup low-sodium chicken broth
- 1 teaspoon salt
- ½ teaspoon black pepper
- ¼ teaspoon garlic powder
- ½ cup frozen peas
- Fresh parsley chopped (for garnish)
Instructions
- Preheat the oven to 350°F (180°C). Lightly grease or spray a 9×13-inch baking dish.
- In a large bowl, whisk together the cream of mushroom soup, sour cream, melted butter, chicken broth, salt, pepper, and garlic powder until smooth.2 cups sour cream, ½ cup unsalted butter, 1 (10 ounces) can cream of mushroom soup, ½ cup low-sodium chicken broth, 1 teaspoon salt, ½ teaspoon black pepper, ¼ teaspoon garlic powder
- Add the cooked spaghetti, chicken, and peas to the sauce. Stir until everything is evenly coated.1 pound cooked chicken, 1 pound thin spaghetti, ½ cup frozen peas
- Pour the mixture into the prepared baking dish. Sprinkle the mozzarella, cheddar, and Parmesan cheese evenly over the top.1 ½ cups shredded mozzarella cheese, ½ cup shredded cheddar cheese, 2 tablespoons grated Parmesan cheese
- Cover with foil and bake for 30 minutes. Remove the foil and bake for another 10–15 minutes, until the cheese is golden and bubbling.
- Let the tetrazzini cool for a few minutes before serving. Garnish with fresh parsley and enjoy!Fresh parsley
Video
Notes
- Bake chicken breasts from scratch: If you’re starting with raw chicken, season chicken breasts with olive oil and bake at 375°F for 25 to 30 minutes until cooked through.
- Try dark meat for extra flavor: Use chicken thighs instead of breast meat for a richer, more flavorful casserole that stays moist.
- Cook pasta properly: Boil the spaghetti noodles in salted pasta water and slightly undercook them by 1 to 2 minutes, since they’ll continue cooking in the oven. Reserve a cup of pasta water before draining it in case you need to thin the sauce.
- Add more veggies: Sauté diced onion until soft, or swap the peas for broccoli, mushrooms, or a mix of veggies.
- Make it ahead: Assemble the casserole up to 24 hours in advance, cover it tightly with plastic wrap, and refrigerate until you’re ready to bake. Add 5 to 10 minutes to the covered baking time if starting from cold.
- Flash-freeze for storage: Let the baked casserole cool completely, cut it into portions, and freeze individual servings on a baking sheet for 1 hour, then transfer them to freezer bags so they don’t stick together.
Nutrition
SERIOUSLY GOOD
CASSEROLES
37 EASY RECIPES designed for days when you want one dish to do all the work for you. Expect rich, mouthwatering layers that are just begging to be on your dinner table.
Immediate eBook download. No physical book available.
Includes ad-free recipes like:
∙ Breakfast Casserole
∙ Cheeseburger Casserole
∙ Four Cheese Ravioli Casserole
∙ Chicken Pot Pie Casserole
∙ Sweet Potato Casserole
...and much more!
How to Store Leftovers
Let the casserole cool completely before storing it. Transfer leftovers to an airtight container and keep them in the fridge for up to 3 days. I use glass food storage containers because they don’t absorb odors and reheat beautifully.
Reheat individual portions in the microwave for 1 to 2 minutes, stirring halfway through, or reheat the whole dish, covered with foil, in a 350°F oven for about 20 minutes, until warmed through. For longer storage, wrap portions tightly in plastic wrap and then in foil, or use freezer-safe containers, and freeze for up to 3 months.
Thaw overnight in the fridge before reheating. The texture stays creamy, and the pasta doesn’t get mushy when reheated gently.
What to Serve With Chicken Tetrazzini
I usually serve this with a simple green salad dressed with balsamic vinaigrette and some crusty garlic bread for soaking up any extra sauce. The casserole is rich and creamy, so the fresh greens balance it out nicely.
Roasted vegetables like broccoli, green beans, or Brussels sprouts also pair well, adding texture and preventing the meal from feeling too heavy. You could also do steamed asparagus or a cucumber-tomato salad if you want something lighter on the side.
More Easy Casserole Recipes for You to Try at Home
I’ve got other easy make-ahead casseroles perfect for family dinners.

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