Add the soaked beans to the pressure cooker along with soaked water, add some salt and pressure cook for 1 whistle.
Pressure cooked beans should be bit firm yet it should get mashed when pressed. Strain the beans and discard the water.
Heat oil in a skillet on medium heat. Once the oil is hot enough add in mustard seeds and cumin seeds and saute.
When it splatters add in chopped green chillies, curry leaves and chopped onions and saute for a 1-2 minutes.
Next add turmeric powder, salt and mix well and let it cook until onion turns soft and translucent.
Add the boiled beans (excluding remaining water) to the pan, mix well. Cook for 3-4 minutes on medium low heat.
FInally add in the fresh grated coconut and mix.
Add some jaggery and mix it well. Continue sauteing for 2-3 minutes.
Finally sprinkle with some fresh coriander leaves and take it off the heat.
Serve it hot as a snack or with rice or roti.