Cook the horsegram in 2 cup of water in a pressure cooker for 6 whistles. Switch off and allow the pressure to go by itself. Drain the water and set aside.

Squeeze out the pulp of tamarind, drain and set aside. Throw away the pressed tamarind.

In a saucepan, heat oil. Splutter the mustard seeds. Add the cumin, black pepper corn and fry briefly. Add the garlic and fry for sometime.

Add the tomato and cook till all mushy. Take out 1/4 cup cooked horse-gram and stir. Switch off and allow to cool. Grind into a thick mixture.

In the same saucepan, heat the oil for tempering. Allow the mustard seeds to splutter. Add in the other tempering ingredients and fry briefly.

Add in the tamarind water, horse-gram water and the ground paste and whisk well Add salt and pepper and simmer for around five minutes.

Add the remaining horse-gram and cook for another couple of minutes. Add in the coriander leaves and switch off.

Serve warm as soup or side dish with rice.