Cut the elephant yam into small cubes and wash it thoroughly. Cook it in enough water by adding turmeric powder and salt. Keep this aside.
Heat oil in a pan and add the mustard seeds. When they pop, add dried Red chilly and cleaned drumstick leaves. (Remove the drum stick leaves from the stems. Wash thoroughly before cooking).
Add ground coconut mixture (Grind coconut coarsely with the shallots, green chilly and cumin powder)and stir well again for 2-3 minutes.
Finally add cooked chena(elephant yam) and combine well. Cover and cook for 2 minutes and turn off the flame.