Soak the chickpeas in water for 4 hours and pressure cook it by adding a little salt. Chop and fry the onions with little oil for 10 min.
Grind the fried onion, tomato, and coriander leaves using a blender.
In a pan heat a little oil and splutter the mustard seeds followed by adding curry leaves. Add the coriander powder and chilli powder fry for 30 sec and then add the tomato onion mixture into it with required amount of water.
When it starts boiling add the cooked chickpeas and tamarind juice and keep it in a medium flame for 20-30 min.