Grind together the chilli powder, coriander powder, turmeric powder, peppercorns, cumin seeds, cinnamon, cloves and cardamoms.
Chop the 2 medium sized onions.
Boil 3-4 cups of water and add to it chopped mutton, ground masala, sliced onions, ginger, garlic, curry leaves, vinegar, coconut pieces and salt. Cook till the meat is tender.
Heat oil in a small pan and add mustard seeds. Allow them to splutter.
Add chopped onions and curry leaves.
When done, add into the mutton gravy and boil for 2-3 minutes.
:- Serve hot with steamed rice.