Soak rajma in enough water for 8 hours or overnight.
Discard the soaking liquid. Add the rajma to a pressure cooker. Add enough water to cover rajma(5-6 cups), salt, and black cardamom. Cover and cook for 3-4 whistles.
Let the pressure release naturally. The rajma should be cooked soft but also holds its shape.
Heat mustard oil in a pan until smokey. Let the oil cool down a bit.
Add bay leaf, cinnamon, cumin, and asafoetida. Cook for 30 seconds until it is aromatic.
Cook onion until it is softened and starts to brown in colour.
Add ginger-garlic paste. Cook for a minute until it is aromatic.
Add turmeric, red chili powder, and coriander powder. cook for 30 seconds until it is aromatic. Take care the spices don't stick to the bottom. Sprinkle little water if the paste sticks to the bottom.
Time to add the pureed tomatoes. Cook everything until tomatoes are cooked thoroughly. The mixture should come together and leave oil around the edge.
Add cooked rajma along with the liquid. , Garam masala and chat masala. Cover and let it simmer for 10-12 minutes.
Towards the end, heat mustard oil in another pan. Add ginger and cook it for 30 seconds. Switch off the flame. Add Kashmiri red chili powder and give it a stir.
Add the tempering, crushed Kasuri methi, and fresh coriander leaves.