1. Pressure cook rajma in plenty of water until it is completely cooked (about 3 whistles) and keep aside.
2. In a blender, grind the coconut with water to make a smooth paste.
3. In a kadai heat some oil. Add cumin seeds.
4. Add curry leaves after the seeds splutter.
5. Add chopped onions and fry till it turns transparent and light brown in colour.
6. Add ginger paste and saute.
7. Add tomatoes and the coconut paste; cook covered until the tomatoes become tender.
8. Add salt, rasam powder, chilli powder, garam masala and the cooked rajma.
9. Cover and cook for another 2 mins
10. Remove from stove, add lemon juice and serve hot with rice or rotis.

Courtesy: http://maneadige.blogspot.com/