Soak the Rajma for 4-5 hours or overnight.
Pressure cook it along with 3 cups of water for 20-25 minutes on medium-high flame.Set aside.
In a Pan,Heat oil.
Add the Cumin(Jeera) & Asafoetida(hing).Let the Cumin Crackle.
To this, add finely chopped onions, garlic,chilli and ginger.Cook till the onions are golden brown.
Sprinkle in the garam masala, chilli powder and coriander powder.Cook for 30 seconds.
Add the pureed tomatoes.Cook till the masala turns red and reduces to half.Keep sautéing.This step takes 10-15 minutes.
You will know the masala is cooked when you see holes in the middle with bubbles forming on the surface.The oil will also separate and you will be able to see it on the surface.
Once the masala is cooked add it to the pressure cooked Rajma along with the sugar.Mix everything together and check the salt.If needed add more.
Return the Rajma to the heat.Pressure cook for another 10 minutes or till well cooked.Usually 2 whistles and no more.
Remove from heat.Let the pressure release automatically.
Check and add more water if the gravy is too thick.If its too thin- Cook it uncovered till desired consistency is achieved.
Garnish with coriander and eat with Rice or parathas.