Grind the coconut, cumin seeds and green chilies into a paste by adding some water. Keep aside.
In a pan add the yam, raw banana, salt and 1 cup water. Bring it to a boil and
simmer, covered till they turns soft but not mushy.
Now add the coconut paste,
Followed by the yoghurt, salt, pepper powder and red chilli powder.
Mix everything well and simmer on a medium flame for 2-3 minutes. Then transfer to a serving dish.
Heat the oil in a pan and temper with mustard seeds and whole red chilli. After it stops spluttering, add the curry leaves and switch off the flame.
Pour the tempering over the prepared kalan. Serve with plain steamed rice, preferably Kerala brown rice.
