Soak black lentils (urad dall) for 3 hours.
Wash the soaked lentils well and grind it adding little water at intervals
Grind black lentils with green chillies and ginger, till it gets soft and fluffy.
Add rice flour, curry leaves,salt and stir the batter well..
Make round balls, flatten them lightly with a hole in the centre and deep fry in oil till they turn golden brown.