Heat the ghee in a large pan. Steam the onions over medium heat while stirring until translucent. Add the garlic, chilli, ginger, turmeric, cumin, coriander and chilli powder. Stir until everything is just heated. Add the meat and brown over high heat until it is coated with the spice mixture, stirring. Stir in the salt and the undrained tomatoes. Cover everything and simmer for 1-1.5 hours until the meat is tender. Stir in coconut milk. Simmer uncovered for another 5 minutes, until the sauce thickens slightly.