Start by seasoning the chicken. Fry the chicken until it's cooked through and browned, then remove from the pan and set aside.
Add the onions and peppers into the same pan and cook until soft, then add the garlic and cook for a minute or so.
Add the uncooked pasta and give it a good mix, then add the stock and cook until the stock has absorbed, then add the milk and turn down the heat so it doesn't split.
Cook this until the pasta has cooked and you're left with a creamy sauce. Add the mustard (optional) and the cheese and mix until the cheese has melted, then season to taste.
Add the chicken back in. Garnish, serve and enjoy.
