Wash and soak the dry kidney beans in about 2-3 cups of water for about 6 hours.
Peel the thick skin of the watermelon and dice them.
Prepare the ginger, garlic and turmeric.
Drain the soaked kidney bean and wash them and set aside
Dice the tomato and set aside.
Soak the tamarind in warm water and extract the pulp
Into the pressure cooker add the nigella seeds, cumin and fennel with 1 tsp of oil ( I have used olive oil) and saute for a minute till the seeds sizzle
Add the ginger, garlic and turmeric root ( if using, if not add the turmeric powder in the next step) and saute for a few seconds
Add the soaked kidney bean, melon, tomato, tamarind, salt, bisibelebath masala and mix well.
Add 2 cups of water and pressure cook for about 5 whistles
Allow pressure to release naturally and then open the lid
Gently mash in a bit of the beans to give a thicker consistency to the curry.
Stir in the chopped herbs and the curry is ready to serve after a taste test,