Soak and sprout the beans 2 days prior to cooking .
Grind coconut and green chilly and make a fine paste.
Boil the sprouts in 1 cup water for 4-5 minutes .
Add oil, mustard seeds, curry leaves, asafoetida and turmeric and add to the sprouts .
Cook for 15 minutes or till the sprouts are tender.
Add tamarind and salt, cook for about 5 minutes .
Add the coconut paste and bring the Usal to a boil .
Temper with mustard seeds , curry leaves and turmeric .
Serve hot with white rice , Masale Bhat or chapatis.