Add all-purpose flour, rice flour, chickpea flour, salt, green chilies, onions, cilantro (coriander leaves), curry leaves, sugar, ginger, and asafoetida (hing) to a large mixing bowl and mix well.
Add sour yogurt (curd) and whisk the batter well to make a smooth thick batter.
Cover the bowl with a lid and let the batter rest for 2-3 hours on the countertop.
Add a pinch of baking soda to the bowl and mix well using fingers for 1-2 minutes. This process aerates the batter and the bonda turns out fluffy.
Heat oil. Drop small portions of batter in the pan using your fingers or a spoon and fry until golden brown. Do not overcrowd the pan. Fry the bajji in small batches.
The bonda will double in size after frying, so drop small ball only. Stir frequently using a large slotted spoon while frying to ensure they fry evenly on all the sides.
Once they are golden brown in color, drain them on a plate lined with paper towels. Serve hot!