Cook pasta in a pot of boiling water according to packet instructions. Drain and transfer to a 10-cup capacity baking dish.

Preheat oven 180°C (fan-forced).

Heat oil in a large non-stick frying pan over medium-high heat. Cook chicken until browned. Transfer to a plate and set aside.

Add onion and mushrooms to the same pan and cook, stirring for 5 minutes. Stir in paprika and flour and mix well.

Stir in tomato sauce, Worcestershire sauce, mustard and chicken stock. Simmer for 5 minutes. Return chicken to pan along with sour cream. Bring to a simmer. Pour onto pasta and mix well.

Top with cheese and bake for 20 minutes or until the top is golden and melted. Garnish with parsley and serve with broccolini.