Take a pressure cooker and put chopped onions, garlic cloves and grated ginger with a splash of water. Close the lid and let it cook for 3-4 whistles.
Let the steam escape naturally.
Open and mash them up with the back of a ladle.
Put it back on flame and let the water evaporate completely.
Put oil in the pressure cooker and now cook the mixture till it separates oil (for about 8-10 minutes) on medium flame.
Add grated tomatoes and let it cook for 5 more minutes.
Add turmeric powder and salt and cook for 2 minutes.
Now add the drained Rajma and cook it for another 5 minutes. Stir in garam masala.
Let it cook on high flame for 2 whistles and then reduce the flame to low and cook for another 20-25 minutes.
Let steam escape naturally.
Remove the lid and adjust salt.
If gravy is too thin, put it back on flame and reduce to your requirement.
Garnish with coriander leaves.
Pair it with roti/parantha or rice.