Wash and soak channa dal and fennel seeds in the water for 3 hours.
Grind the dal and fennel coarsely in food processor or blender adding a few spoons of water if necessary.
Finely chop peeled onion, chillies, curry leaves and coriander leaves and add to dal batter.
Mix in salt and jeera dhania powder.
The batter should hold its shape when pressed between palms.
Heat oil for frying.
Keep a bowl of water at your work station. Dip your fingers in water, about 3 tablespoon of batter on your palm and shape it into a ball and then flatten the top to make a patty or vada.
Fry until until dark brown.
Serve hot with chutney.
Hot oil test - To know whether the oil is ready for frying put a tiny ball of batter into the hot oil and count one thousand one, one thousand two and one thousand three. If the ball rises to the top, the oil is ready for frying. If not, for a minute and repeat test.
You can also uses these vadas for making koftas. Make a gravy of onions, ginger and garlic (see Shahi Paneer recipe for gravy details) and boil the vadas in it.