Semi crush the rajma(dry) in a mixer for 2-3 secs.
Pressure cook rajma and whole black urad with about 10 cups of water (whole urad needs lots of water to cook) adding 1/2 tsp salt and finely cut ginger up to 8 - 10 whistles.
Let the cooker cool off and check if the lentils are cooked thoroughly. If not add little water and keep on a low flame for 10 mins.