Heat the oil and butter in a large saucepan and sauté the onions until soft.
Add the chilli powder (or chilli), ground coriander, cumin, garlic, ginger, cardamom and turmeric and stir-fry for 1 minute or until fragrant.
Add the yoghurt, salt, tomatoes, sugar and chutney and simmer for about 10 minutes.
Add the meat and stir to coat with the sauce.
Cover and simmer over low heat for 60-90 minutes or until the meat is tender.
Remove the lid and simmer for another 10 minutes to thicken the sauce.
Stir in the garam masala and scatter the fresh coriander on top just before serving.
Serve with rice.