Wash and rinse the lentils separately for at least 4 hours.
Grind the Urad dal with just enough water to a fluffy batter.
Save 2 tsp of chana dal and grind the rest of the Chana dal to a semi coarse paste.
Make a paste of ginger and 3 green chilies, finely chop one chili.
Wash and finely chop the spinach leaves.
In a wide bowl, add all the ingredients together.
Heat a Kadai with oil, take a small portion of batter, flatten as you would with your regular vadas, and gently slide into the hot oil.
Cook on a medium flame for the vadas to be cooked from within as well.
Cook on both sides and drain with a slotted ladle onto a kitchen towel.
Serve hot with chutney.