Ingredients:

  • 1 pound Spaghetti
  • 3 cups, shredded Cooked Chicken
  • Salt (for pasta water)
  • 4 tablespoons Unsalted Butter
  • 1 medium Yellow Onion, finely diced
  • 1 small Green Bell Pepper, finely diced
  • 3 cloves Garlic, minced
  • 4 tablespoons All-Purpose Flour
  • 1 cup Whole Milk, warmed
  • 3 cups Chicken Stock (low sodium), warmed
  • 1 (14.5-oz) can Diced Tomatoes (canned, undrained)
  • 4 ounces Cream Cheese, cubed (room temperature)
  • 1 teaspoon Worcestershire Sauce
  • 1 teaspoon Smoked Paprika (Optional)
  • 3 cups Sharp Cheddar Cheese, shredded (Divided)
  • Salt and Black Pepper (To taste)
  • ½ cup Reserved Pasta Water

Instructions:

  1. Preheat the oven to 375°F (190°C). Grease the 9x13 inch baking dish. Ensure all vegetables are chopped and cheese is shredded.
  2. Cook Pasta: Boil the spaghetti in heavily salted water until al dente (usually 1-2 minutes shy of package directions). Drain, reserving at least ½ cup (120ml) of the starchy pasta water. Toss the drained pasta with a drizzle of oil to prevent sticking.
  3. Prepare Chicken: If not using pre-cooked rotisserie chicken, boil or roast the chicken breasts until cooked through (165°F/74°C). Shred immediately and set aside.
  4. Sauté Aromatics: Melt the butter in a Dutch oven over medium heat. Add the diced onion and bell pepper and sauté gently for 6–8 minutes until softened. Add the minced garlic and cook for 1 minute until fragrant.
  5. Create the Roux: Sprinkle the 4 tablespoons of flour over the sautéed vegetables. Stir continuously for 2–3 minutes until the roux looks like wet sand and smells nutty.
  6. Thicken the Liquid: Gradually whisk in the warmed chicken stock, followed by the warmed milk, ensuring the liquid is added slowly to prevent lumps. Bring the sauce to a gentle simmer, stirring frequently, until it has noticeably thickened (about 5 minutes).
  7. Finish the Sauce: Reduce the heat to low. Stir in the canned diced tomatoes (undrained), the cubed cream cheese, Worcestershire sauce, and smoked paprika. Stir until the cream cheese is fully melted and the sauce is smooth and luxurious.
  8. Season: Taste and adjust seasoning generously with salt and pepper. If the sauce is too thick, stir in a splash of the reserved pasta water until the desired consistency is achieved.
  9. Combine: Remove the sauce from the heat. Stir in the shredded chicken and 2 cups of the shredded sharp cheddar cheese until the cheese is melted and incorporated.
  10. Mix and Transfer: Add the cooked spaghetti to the sauce mixture. Use tongs to gently toss everything until the pasta is fully coated. Pour the mixture into the prepared baking dish.
  11. Top and Bake: Sprinkle the remaining 1 cup of sharp cheddar cheese evenly over the top. Bake for 35–40 minutes, or until the casserole is bubbling hot throughout and the top is golden brown.
  12. Rest: Let the casserole rest for 10–15 minutes after removing it from the oven before serving. This allows the sauce to set up perfectly.