In a bowl, add besan, corn flour, rice flour, turmeric powder, dhanajeera powder, chili powder, green chilies, ajwain, baking soda & salt and give it a good mix.
Slowly add water to it so that it has a thick pouring consistency. Make sure there are no lumps.
Then add the onions to this and mix it well so that the onions are well coated with the batter.
In a deep-bottomed pan, heat some oil.
Scoop out the onion mixture bit by bit and add it into the hot oil.
Fry these bhajis till they turn golden brown.