In a wide bowl add chickpea flour, salt, red chilly powder, carom seeds and turmeric powder.Give a quick mix so that spices combine with chickpea flour. Next add water little by little and make moderate thick batter. Also add cooking soda now (if adding) and mix. The consistency of batter should be such that thick layer should get coated on chillies.
Heat cooking oil in a wide wok and when it's rightly heated proceed to next step. Check the oil by dropping a drop of batter in to it, if it raises to the top immediately the oil has reached right temperature.
Now dip the slit bajji chillies in the batter. Holding the stem of the chilly, rotate it in batter so that thick layer of batter coats over it. Carefully drop the chillies in to hot oil batch-wise. When the bajji cooks to golden brown in all the sides, using slotted ladle remove and drain on kitchen tissue paper.
Hot hot mirchy bajji is ready to serve as tea time snack.