Cut shalgam into cubes. Heat oil in a pan. Add jeera, kalonji and ginger. Add tomatoes and cook. Add coriander, turmeric and red chilli powder. Mix well. Add shalgam and water. Stir. Add chopped coriander and mint and roasted chana dal. Add salt. Cook till shalgam is tender and sauce is thick. Finally add garam masala powder and serve hot.