Wash and soak beans overnight or 7-8 hours in adequate water.
Next day drain it and keep aside.
Heat oil in a pressure cooker, and add mustard seeds, cumin seeds, carom seeds, dry red chili and pinch of hing.
Once seeds popup, add soaked beans, 1 cup water, red chili powder, turmeric powder, tamarind pulp, jaggery, salt and mix it well.
Cover a lid of the pressure cooker and cook it till 5-6 whistle on medium flame.
Allow to cool down, remove the lid, press some beans with spoon for thick gravy, add grated coconut and boil it for few minutes.
Rangooni Vaal Shaak is ready. Add chopped coriander leaves and serve it with roti, steamed rice or any Indian Flat bread.