cook the chopped raw banana and yam with 2-3 cups water, turmeric powder, pepper and salt until soft.
grind coconut, cumin, green chilli and curd to a very fine paste.
add the coconut paste to the cooked vegetable and mix well with spoon or fork
after a minute, add the whisked curd and butter. mix well
lastly add ghee and mix well. let it get heated up. put off flame and take it off stove.
for seasoning. heat coconut oil and pop in mustard seeds, cumin seeds, curry leaves, fenugreek seeds and red chilli.
add the seasoning to the curry and mix well.