Special thanks to my mum for this one.
Marinate meat in lemon juice, salt and yoghurt overnight.
Melt butter in a heavy pan, add onions and garlic and fry gently until soft, add spices and seasoning, then fry for a further 3 min, stirring constantly. Stir in the meat and marinade and fry for a further 10 min, stirring ocasionally. Add tomato puree and water. Cover with a tight fitting lid and simmer for 45 min to 1 hour or until sauce is thick and meat is tender.
Serve hot with rice.