Marinate the cleaned and cut mutton pieces with 1/2 cup plain yoghurt and set aside for 30 mins.
Heat oil in a wok.
Saute the onions, garlic, ginger and the tomatoes on low flame.
When the onions are golden brown and the tomatoes are well mashed and the oil comes clear, add the turmeric powder, the meat masala, the black pepper powder, the chillie powder, salt and half the curry leaves and saute for another 3 - 4 mins.
Add the marinated meat and water as required and cook till meat is well cooked.
When the meat is half cooked, add the remaining curry leaves.
:- You can pressure cook to make it faster, I prefer to cook it in the wok as the meat comes out fine and not too soft.
Garnish with tomato slices.
:- Serve with rice or roti.