Wash and soak rajma overnight or 7-8 hours.
Drain and presser cook the rajma with required water (1½ -2 cup) and salt for 4-5 whistle or till cook, and keep aside till cool down the pressure cooker.
After cool down remove the rajma from the pressure cooker, drain it and keep aside. Do not throw the beans stock/water. You can use it in a gravy.
Heat the butter or ghee in a pan. Add cumin seeds, bay leaves, big cardamoms, asafoetida/hing, chopped onion and saut it till caramelized or golden brown.
Add ginger-garlic-green chili paste, mix well and then add tomato puree in the prepared mixture.
Add red chili powder, turmeric, coriander powder,garam masala, salt and mix well, saut it for 4-5 minutes or till mixture leave the fat.
Add cooked rajma, 1 cup water (use leftover beans stock) and mix it well, bring it to the boil and cook till the gravy is thickened enough. You can mash some cooked rajma with spatula, it will make your gravy thicker and tasty.
Add amchoor powder, kasuri methi (crush between your hand palms and sprinkle), white butter and mix well, cook it for 2 minutes.
Rajma Masala is ready garnish with chopped coriander leaves, and serve with steamed rice, roti or naan along with chopped onion and lemon wedge.