Take the curds, beat it into a smooth paste, add salt. Mix it with 100 ml of water.
It should be of medium thickness consistency. Let it stay for 10 to 15 mins.
Cut Onions into rings, making sure you remove the stack in the middle. Shred into separate rings as shown in the picture.
Take Maida in a bowl. Add baking soda and chili powder.
Pour the buttermilk little by little, to get a uniform paste making sure there are no lumps. Then add all the buttermilk to get a medium consistency. The batter should not be so thick.
Heat oil in a pan. Once it's really hot, dip the onion rings in the batter and drop them into the oil.
Once they are fried well, remove them to a kitchen paper. You will have to remove them once they turn light golden in colour.
Serve it with a little chili powder sprinkled on the top.