Clean, wash and drain the mutton pieces and keep aside..
Fry turmeric powder, kashmiri chilly powder and coriander powder together in a pan without oil to remove the raw smell and taste of these powders.
Marinate the mutton pieces with the fried masala powders, 1 tsp garam masala and salt. Keep aside.
Heat coconut oil in a kadai and saute sliced shallots, chopped ginger & garlic and curry leaves till shallots becomes soft. (Instead of shallots, you can use 4 big onions).
Add chopped tomato and saute till it is mashed well in the masala.
To this, add the marinated mutton pieces along with remaining 1 tsp garam masala and required quantity of hot water.
Cover and cook it in a medium flame till the meat is cooked well and the curry reaches a medium thick gravy consistency. Refer tips.
Make sure there is enough water while cooking the dish.
Serve hot with steamed rice / kappa / chappathi / appam / idiyappam.
Notes
If you are cooking it in a pressure cooker, don't add water. Keep the
marinated mutton along with the shallot masala in the cooker, close it and keep it in a low flame and cook for 1 whistle. If you are cooking it in a pan/kadai, add required quantity of water and cook it on a medium flame for about 45 minutes to 1 hour or till the meat is cooked well. Make sure there is enough water till it is done.