Heat butter and half the oil in a non-stick saucepan.
Add onion, thyme and cayenne pepper and slowly cook over a low heat until onion is soft and sweet but not brown.
Add mushrooms and gently fry for three minutes.
Remove and set aside.
Using the same pan, heat remaining oil until smoking.
Flash-fry beef in batches, seasoning as you go, then set aside.
Return onion to pan and add sour cream. Bring to the boil and simmer for a minute or until thickened.
Return steak to pan and heat very gently for a minute – the beef shouldn't be cooked any further.
Stir in lemon juice, Worcestershire sauce and parsley, season and serve with mashed potatoes, pasta or rice.This recipe is sponsored by Pick n Pay and was created by Fresh Living magazine.