Soak Chana daal in water for about 6 hours. Drain and grind 3/4th of it to fine paste using as little water as possible. Take half of the rest and grind coarsely. Keep the rest as is and mix all parts well in a bowl.
Chop the onions , green chillies and curry leaves into fine pieces. Add ginger paste, sprinkle asafoetida , add salt and mix all .
Add the above mixture to the bowl containing chana daal, mix well. Set aside for about 10-15 minutes.
Heat oil in a deep frying pan and when the oil is hot enough, make small to medium sized patties of the daal mixture and deep fry.