1. Soak moong dal for 3 hours and grind into a fine paste using a little water along with red chilies, ginger and cumin seeds.
2. Don`t make it too watery.
3. Crush idlis coarsely with hand and add this to the moong dal batter and mix well.
4. Add onions, cilantro and salt to the batter and mix well. If the batter turns too watery add some rice flour and mix well. The batter should be thick so it would be easy to make round shapes for vadas.
5. In a deep pan add oil and heat. Then take small portions of batter, shape into a circle and carefully drop into the hot oil.
6. Fry till the vadas turn golden brown in color.
7. Remove from oil and place on a paper towel to drain excess oil.
8. Repeat the same process with rest of the batter.
9. Enjoy these crispy vadas with a cup of coffee/tea.
10. Use any desired chutney as a dip for these vadas.

Recipe courtesy: Trendy Relish