Ingredients
- 12 oz spaghetti, cooked al dente
- 2 cups cooked chicken (shredded or diced)
- 10.5 oz can cream of chicken soup
- 10 oz can Rotel tomatoes with green chilies
- 1 cup chicken broth
- 1 small onion, diced
- 1 small bell pepper, diced
- 1 jalapeño, finely chopped (optional)
- 1 teaspoon garlic powder
- 1 teaspoon smoked paprika
- 1/2 teaspoon cayenne pepper (optional, to taste)
- 2 cups shredded cheddar cheese, divided
- 1 cup shredded Monterey Jack or Pepper Jack cheese
- 2 tablespoons olive oil
- Salt and pepper, to taste
Equipment
- 9×13‑inch casserole dish
- Large mixing bowl
- Skillet
- Wooden spoon or spatula
- Cheese grater (if shredding fresh cheese)
Ingredient notes
- Spaghetti (12 oz, al dente): Cooking the pasta to just al dente is important because it will continue to cook and absorb liquid in the oven; overcooked pasta can turn mushy.
- Cooked chicken (2 cups): Any cooked shredded or diced chicken works—rotisserie is especially convenient and flavorful. Dice or shred into bite‑size pieces so it distributes evenly through the casserole.
- Cream of chicken soup + broth: The condensed soup and broth together form a creamy, pourable sauce that clings to the spaghetti and chicken, creating that classic Southern casserole texture.
- Rotel tomatoes with green chilies: Rotel adds acidity, tomato sweetness, and mild heat that balance all the cheese and creaminess. Most Southern chicken spaghetti casseroles lean on Rotel for this signature flavor.
- Cheddar + Monterey Jack/Pepper Jack: Cheddar gives sharp, comforting flavor, while Monterey Jack melts smoothly; Pepper Jack adds extra spice if you want more heat. Using a blend gives the best flavor and texture.
- Onion, bell pepper, jalapeño: Sautéed aromatics add sweetness, texture, and depth. Jalapeño is optional but brings a nice Southern “kick” if you enjoy spice.
Step‑by‑step instructions
Step 1: Preheat the oven and prep the dish
Preheat the oven to 350°F (175°C). Grease a 9×13‑inch casserole dish with nonstick spray or a light coating of oil to prevent sticking and make serving easier.
If you haven’t already, cook the spaghetti in well‑salted water according to package directions until al dente. Drain and set aside.
Step 2: Sauté the vegetables
In a skillet over medium heat, heat the 2 tablespoons of olive oil. Add the diced onion, diced bell pepper, and jalapeño (if using). Sauté, stirring occasionally, until the vegetables are softened and the onions are translucent. This should take about 5–7 minutes. Season lightly with salt and pepper. Remove from heat.
Step 3: Mix the creamy base
In a large mixing bowl, combine the cream of chicken soup, Rotel tomatoes (with their juices), chicken broth, garlic powder, smoked paprika, cayenne pepper (if using), and 1 1/2 cups of the shredded cheddar cheese. Stir until everything is well mixed and the cheese is evenly distributed through the sauce.
Step 4: Add spaghetti, chicken, and veggies
Add the cooked spaghetti and the cooked chicken to the bowl with the sauce mixture. Then add the sautéed onions, bell pepper, and jalapeño. Toss gently with tongs or a large spoon until the pasta, chicken, and vegetables are well coated and everything is evenly combined. The mixture should be saucy but not soupy; remember it will thicken as it bakes.
Step 5: Transfer to the casserole dish and top with cheese
Pour or spoon the spaghetti mixture into the prepared 9×13‑inch casserole dish, spreading it into an even layer. Sprinkle the remaining 1/2 cup cheddar cheese over the top, followed by the 1 cup shredded Monterey Jack or Pepper Jack cheese. This double‑cheese topping will melt into a bubbly, golden layer.
Step 6: Bake
Bake in the preheated 350°F (175°C) oven for about 30 minutes, or until the casserole is hot and bubbly and the cheese on top is melted and lightly golden. If you like extra browning, you can broil for 1–2 minutes at the end, watching closely so it doesn’t burn.
Let the casserole rest for 5–10 minutes before serving so it can set slightly and is easier to scoop neatly.