01 -
Heat a drizzle of oil in a skillet over medium heat. Cook the chicken breasts for 6 to 8 minutes per side until golden brown and cooked through. Remove from pan and let rest before dicing into small cubes.
02 -
Meanwhile, bring a large pot of salted water to a boil. Cook the macaroni following package instructions until al dente. Drain and set aside.
03 -
In the same skillet, melt butter over medium heat. Whisk in flour and cook for 1 to 2 minutes until the mixture turns a light golden color, forming a roux.
04 -
Gradually whisk in the milk, stirring continuously to prevent lumps. Cook until sauce thickens, 3 to 5 minutes. Reduce heat and stir in Cheddar, Mozzarella, and Parmesan until fully melted and smooth.
05 -
Add mustard if using, then season with salt, black pepper, garlic powder, and paprika. Stir thoroughly to combine flavors.
06 -
Add cooked macaroni and diced chicken to the cheese sauce. Stir gently until pasta and chicken are evenly coated.
07 -
For a golden crust, transfer mixture to an oven-safe dish and broil under high heat for 3 to 5 minutes. Remove before the topping burns.
08 -
Sprinkle with freshly chopped parsley and serve immediately while warm.