Take the peppers and slit at the center and remove seeds.
For batter, in a mixing bowl, add gram and rice flour, carom seeds, baking soda and salt. Mix well.
Add water to the dry ingredients and mix well to prepare smooth batter. Make sure there are no lumps.
Add 1 Tbsp of hot oil over the batter and mix well.
Dip the pepper and coat it with batter on all sides.
Slowly drop the peppers into the hot oil and deep fry them.
Gently flip them and fry until all the sides are golden brown.
Slit the bajji with a knife and stuff the slit with chopped onion with a spoon and sprinkle a pinch of chat masala on the bajji.
Serve hot with tea or coffee.