Cook dal with ½ cup of water. Don’t overcook or mash the dal. Grind coconut, cumin seeds and green chilly together to get a fine paste. Cook banana in a deep vessel with little water and turmeric powder. When almost done add dal and salt and pepper. Meanwhile heat oil in a pan and add mustard seeds and when they crackle add urid dal and red chilly and fry till browned. Now add ground coconut and curry leaves and fry till coconut is golden brown. Add this to Banana and dal which almost done. Cook on low heat till gravy is thick (almost dry) Serve hot with rice.