Name: Chicken Spaghetti
Prep time: 20 min
Cook time: 15 min
Total time: 35 min
Cuisine: American
Ingredients: Cooked chicken (rotisserie, leftover, or fresh); Spaghetti (thin spaghetti preferred); 1 onion, diced; 2–3 cloves garlic, minced; 2 tbsp butter; 2 tbsp all-purpose flour; 1 cup chicken broth; 1 cup milk; 4 oz cream cheese; 1 1/2 cups shredded cheddar cheese; 1 can Rotel tomatoes (diced tomatoes with green chilies); 1 cup shredded mozzarella (for topping); 1 tbsp olive oil; Salt, pepper, Italian seasoning; Red pepper flakes and chopped parsley (optional garnish)

Jump to Recipe·Leave a Review

This creamy Chicken Spaghetti is comfort food at its best—a cheesy, satisfying casserole full of tender chicken, spaghetti, and flavorful Rotel tomatoes. I love how this dish skips the canned soup and instead builds flavor from scratch with a three-cheese blend and a simple homemade cream sauce.

Why You’ll Love This Recipe

I reach for this recipe when I want something that feels indulgent yet simple to pull together. It’s great for using up rotisserie or leftover chicken, and I can prep it ahead of time, refrigerate, or even freeze it for later. The rich combination of cheddar, cream cheese, and mozzarella melts beautifully into a velvety sauce that coats every bite. Plus, it’s baked until bubbly and golden—pure comfort in a casserole dish. Chicken Spaghetti

Ingredients

(Here’s a tip: Check out the full list of ingredients and measurements in the recipe card below.)

Cooked chicken (fresh, leftover, or rotisserie)
Spaghetti (thin spaghetti preferred, but any pasta works)
Onion, diced
Garlic, minced
Butter
All-purpose flour
Chicken broth
Milk
Cream cheese
Cheddar cheese, shredded
Rotel tomatoes (diced tomatoes with green chilies)
Mozzarella cheese, shredded (for topping)
Olive oil
Salt, pepper, and Italian seasoning
Red pepper flakes and chopped parsley (for garnish, optional)

Directions

If I’m using fresh chicken, I season it with salt, pepper, and Italian seasoning, then sear it in olive oil until golden and cooked through. I dice it and set it aside. Leftover or rotisserie chicken works perfectly too.

In the same skillet, I melt butter and sauté the onions and garlic until softened. I sprinkle in flour and cook for a couple of minutes to form a roux. Then, I slowly add chicken broth and milk, stirring constantly until the mixture thickens.

While the sauce simmers, I cook the spaghetti in a separate pot according to package directions and drain it well.

I stir the cream cheese into the sauce, followed by the shredded cheddar. Once smooth, I add the Rotel tomatoes, cooked chicken, and drained pasta. I stir until everything is well combined, then transfer it to a casserole dish.

I top the casserole with shredded mozzarella and bake at 400°F for 15 minutes. If I want an extra bubbly, browned top, I broil it for a couple of minutes at the end. I finish with red pepper flakes and chopped parsley for a pop of color and heat.

Servings and timing

This recipe makes 6–8 servings.
Prep Time: 20 minutes
Cook Time: 15 minutes
Total Time: 35 minutes

Variations

Sometimes I swap spaghetti for penne or rotini when I want more texture. I’ve also used pepper jack instead of cheddar for extra spice, or added sautéed bell peppers and mushrooms for more veggies. If I need a gluten-free version, I just use GF pasta and flour in the sauce—it works beautifully.

Storage/Reheating

I store leftovers in an airtight container in the fridge for up to 3 days. To reheat, I use the microwave for single servings or warm the entire dish, covered, in a 350°F oven until heated through.

To freeze, I let the assembled casserole cool, then cover tightly and freeze for up to 3 months. When I’m ready to serve, I thaw it in the fridge overnight and bake at 350°F for about 30–35 minutes until hot.

FAQs

Can I use canned chicken for this recipe?

Yes, though I prefer rotisserie or freshly cooked chicken for the best texture and flavor.

Do I need to cook the pasta before adding it to the casserole?

Yes, I always cook and drain the spaghetti first. It ensures the pasta is perfectly tender and blends easily with the sauce.

Can I make this ahead of time?

Absolutely. I assemble the whole dish, cover it, and refrigerate it for up to 2 days. When ready, I bake it covered for 20 minutes, then uncover and finish baking.

Why is my sauce grainy?

Grainy sauce usually happens when the cheese is added to a sauce that’s too hot. I reduce the heat before adding shredded cheddar and stir slowly until it melts.

Is this recipe spicy?

The Rotel adds mild heat. If I want more spice, I sprinkle in red pepper flakes or use spicy Rotel. For a milder dish, I use plain diced tomatoes instead.

Conclusion

This Chicken Spaghetti casserole is one of those reliable, go-to dinners that I can count on to satisfy everyone at the table. It’s rich, cheesy, and full of cozy flavors that feel like a warm hug. Whether I’m making it for a weeknight dinner, a potluck, or a freezer meal, it always earns rave reviews.