Soak the black chickpeas overnight and pressure cook for 5 – 6 whistles or until soft. Set aside.
Heat a teaspoon of oil in a pan. Add the sliced onions and green chilli and fry until transparent. Add turmeric powder, chopped tomatoes and water and cook until tomatoes are mushy.
Add the cooked chickpeas, tamarind extract, salt, red chilli powder, jaggery and water (adjust to desired consistency).
Dilute the rice flour and little water and add it to the chickpeas mixture. Mix everything.
Let it boil for 8 – 10 minutes.
Add the desiccated coconut and coriander leaves and mix well. Turn off the flame.
Heat oil in a pan for seasoning. Add mustard seeds, cumin seeds and fenugreek seeds and let them splutter. Add hing and turn off the flame. Pour this over the prepared chickpea stew and combine.