In a deep bottomed pan, add mustard oil, when it gets heated add green cardamom, black cardamom, cinnamon, clove, peppercorn. Once they become fragrant, add onions and cook till they are golden brown. Now add the tomatoes and cook on high for 4-5 minutes. Add ginger- garlic-chilli paste, cumin powder, coriander powder and black pepper powder. Cook till the spices become fragrant and oil starts leaving the sides of the pan. Now add the rajma and one cup of water. Mix well and cook covered for 10 minutes. Once done, add the ghee. You can garnish with coriander leaves. Your rajma is ready.