Beef and tomato Stroganoff

1) Cut steaks into thin strips about 2.5cm long. Coat with seasoned flour.
2) Heat butter and oil in a frying pan, add steak and onion and fry for 3-4 minutes, until meat is browned on all sides.
3) Add mushrooms and fry for 2-3 minutes.
4) Stir in paprika and salt and fry for 1 minute.
4) Blitz or mash chopped tomatoes and add, cook for 4-5 minutes.
5) Lower heat, add parsley and soured cream, reserving a little for serving,and heat through.
6) To serve top with the reserved sour cream