Soak the vaal overnight or 6 hours and then discard all the water and keep covered overnight or at least 6-8 hours for sprouting.
Take handful of the vaal on your hand and press one side of each Vaal to remove the skin. Discard any vaal having black spots.
Wash thoroughly with water and keep aside.

Now add hot water (approximately 1 cup) and cover and cook.
Keep some water on the plate covered. This will help the val to cook consistently and faster.
Now check if vaal is cooked well and add cumin powder and some more hot water as per the curry consistency you like.
Garnish with some chopped fresh coriander leaves and serve with rice.