Drain and rinse the soaked kidney beans, then cook them in fresh water until completely tender and creamy inside, either in a pressure cooker or a heavy pot. Heat the oil or ghee in a separate heavy-bottomed pan and add the cumin seeds and bay leaf. Once fragrant, add the chopped onion and sauté until golden brown. Stir in the ginger-garlic paste and green chilies and cook for another minute, then add the tomatoes, turmeric, chili powder, coriander, cumin, black pepper, and salt. Cook the masala over medium heat until the tomatoes break down and the oil begins to separate from the mixture. Add the cooked kidney beans along with some of their cooking liquid and gently simmer for 20–25 minutes, stirring occasionally and lightly crushing a few beans against the side of the pot to naturally thicken the gravy. Stir in the garam masala and simmer for another 2–3 minutes. Meanwhile, cook the basmati rice separately until fluffy. Finish the rajma with fresh coriander and a little lemon juice, then serve generously over hot steamed rice.