Trim both ends of the bananas, and peel a thin layer off the skin. Cut each one lengthwise into half and cut each half into half inch thick pieces. Put these into a saucepan or pot and add enough water to just cover them. Add the crushed black pepper, turmeric powder and salt. Stir and bring to a boil. Cover and let it cook till soft but the pieces are still firm enough to hold shape. They should not become mushy.

In the meanwhile, grind the coconut, cumin and green chillies with a little water into a smooth fine paste. Put this paste, the thick yogurt and the chickpea flour in a bowl and whisk lightly till smooth.

Once the banana is cooked, stir in the yogurt-coconut mixture. Cook over medium heat until the Kaalan comes to a boil. Do not let it continue to boil and take it off the heat.

Heat the oil for tempering. Add the mustard seeds and when they splutter add the crushed fenugreek seeds, the red chillies and curry leaves. Take off the heat and pour into the Kaalan. Cover the saucepan and let it sit for about 10 to 15 minutes for the flavour to develop.

Stir and serve hot, with rice.