Put the gram flour in a large bowl.
Stir in enough water to make a thick batter.
Add the bicarbonate of soda and ajwain seeds and season with salt.
Add the onion rinds and mix well, to coat the onion in the batter.
Heat enough oil for deep-frying in a kadai or deep, heavy-based pan to 180 degree C / 350 degree F, or until a cube of bread browns in 30 seconds.
Using a ladle, very carefully drop spoonfuls of coated onions into the hot oil.
Deep-fry for about 3-4 minutes, or until golden brown.
Remove with a slotted spoon and drain on kitchen paper (paper towel).
Keep the fritters warm, while making the others in the same way.