Soak beans overnight in water and 1/4 tsp soda bi-carb.
Boil till tender and till there are 2 cups water left.
Strain out the liquid and keep aside.
Heat oil, fry onions, chillies and ginger till brown, add in yoghurt, salt and rajmah water.
When it boils, put in rajmah and coriander leaves, simmer till thick.
Add garam masala.
Whilst serving, put top of the milk on top.