Dry roast the spices and grind them into a coarse powder but more on a smooth texture.
Take the sliced onions in a bowl and add salt and chili powder.
Rub well so that it coats the onions well. Next, add the spice powder and mix well.
Now sprinkle the besan over it and mix again along with cooking soda.
Sprinkle a few drops of water to get a firm thick batter.
Heat the Kadai with cooking oil.
When the oil becomes hot, take a big chunk of the batter and flatten it.
Gently drop into hot oil and deep fry till golden on both sides.
Drain using a slotted ladle.