Wash black urad dal a couple of times and soak in water overnight.

Soak kidney bean  in another bowl .

The next day, put the soaked urad dal in a colander for sometime.

Now, clean the lentil. Some of them are hard as pellets and will never cook. They need to be discarded.

In a bowl, add the cleaned lentils and kidney beans with three cups of water. Cut the green chilli into two pieces and throw it. Put the grated ginger and a little turmeric powder to it. Pressure cook for five or six whistles.

In another pressure pan, add butter. Add cumin, as it splutters, put onion pieces. Saute it for sometime, until light pink in colour. Put tomato  in it. Saute it. Once it is mushy, add the cooked lentil and bean mixture to it. Put salt. Allow it to simmer for sometime. Put chilli powder and pepper powder. Check the consistency, add water accordingly. The consistency, will be thicker on cooling, you need a medium, flowing consistency. Pressure cook for one whistle.

Once the pressure release, check the taste and adjust accordingly. Garnish with fresh coriander.