Ingredients:

  • Spaghetti: 400 g (14 oz)
  • Water and Salt: For boiling pasta
  • Cooked Chicken Breast (shredded): 600 g (21 oz)
  • Olive Oil (light): 1 tbsp
  • Unsalted Butter: 4 tbsp (56 g)
  • Yellow Onion (finely diced): 1 medium
  • Garlic (minced): 3 cloves
  • Roasted Red Peppers (jarred, drained and chopped): 120 g (4 oz)
  • Smoked Paprika: 1 tsp
  • Dried Thyme: ½ tsp
  • All-Purpose Flour: 4 tbsp (30 g)
  • Whole Milk (warm): 700 ml (3 cups)
  • Low-Sodium Chicken Stock: 120 ml (½ cup)
  • Worcestershire Sauce: 1 tsp
  • Salt and Freshly Ground Black Pepper: To taste
  • Sharp Mature Cheddar (grated): 250 g (9 oz)
  • Parmesan Cheese (finely grated): 3 tbsp
  • Panko Breadcrumbs: ½ cup (45 g)
  • Butter (melted, for topping): 1 tbsp

Instructions:

  1. Preheat oven to 190°C (375°F). Lightly grease the 9x13 inch casserole dish.
  2. Cook the Pasta: Boil the spaghetti in heavily salted water until al dente (1-2 minutes less than package directions). Drain immediately and toss lightly with 1 tbsp olive oil to prevent sticking. Set aside.
  3. Shred and Chop: Ensure chicken is shredded. Dice the onion and chop the roasted red peppers.
  4. Sauté Aromatics: Melt the 4 tbsp butter in the saucepan over medium heat. Add the diced onion and sauté until softened (about 4 minutes). Add garlic, smoked paprika, and dried thyme; cook for 1 minute until fragrant.
  5. Create the Roux: Sprinkle the flour over the butter and onion mixture. Whisk continuously for 1–2 minutes until a thick, golden paste (the roux) forms. This cooks out the raw flour taste.
  6. Add Liquids: Slowly pour in the warm milk, whisking constantly to prevent lumps. Once smooth, whisk in the chicken stock and Worcestershire sauce.
  7. Simmer and Thicken: Bring the mixture to a gentle bubble, then reduce heat to low. Simmer for 5-7 minutes until the sauce is thick enough to coat the back of a spoon.
  8. Add Cheese and Season: Remove the pan from the heat. Stir in 200 g of the grated Cheddar and all of the Parmesan until smooth. Season heavily with salt and black pepper. Taste test and adjust seasoning—the sauce should be robust.
  9. Combine: Add the cooked spaghetti, shredded chicken, and chopped roasted red peppers directly into the sauce. Gently toss everything until the pasta and chicken are evenly coated.
  10. Assemble Casserole: Transfer the mixture into the prepared casserole dish, spreading it into an even layer.
  11. Prepare Topping: In a small bowl, combine the Panko breadcrumbs with the melted butter and the remaining 50g of Cheddar cheese. Mix well.
  12. Top and Bake: Sprinkle the breadcrumb/cheese mixture evenly over the casserole. Bake for 25–30 minutes, or until the sauce is bubbling around the edges and the topping is deeply golden brown and crunchy.
  13. Rest and Serve: Let the casserole rest for 5-10 minutes before serving.