Soak black gram dal and rice for 4 hours. Rinse thoroughly and keep aside.
Grind them by adding little water to get thick and soft consistency.
Add chopped onion, green chilies and coriander leaves. Add salt and mix well.
Heat oil for deep frying on low flame.
Take a small portion of the batter, make round shape balls and drop into oil carefully.
Turn the flame to medium high and cook till they turn into golden brown color.
Repeat the process until the batter is done.
Serve hot with peanut or coconut chutney.