how long to leave the sliced onion mixed with salt/pepper for onion Bhaji/onion fritters/onion pakoras?
There are more than one methods and answers to above question. As per the Mumbai Special Ghati Bhajiya, Sliced Onions must be mixed with Salt for at least 15 Minutes &amp; Maximum for 1/2 Hour. The water content must than be drained keeping only dry salted onions. Then Gram flour &amp; other Spices should be added to Onions, just to bind, so Bhajiyas or Pakoras can be made.
Taste of Onion in Bhajiyas or Pakoras turns slightly mild, yet crispy, because due to low water content onion cook fast without turning dark!

Rice Flour, it can also be added or can be a substitute of gram flour for crispy Bhajiyas. Rice flour should be coarse and not fine.
For Crispness Ratio of Rice Flour to Gram Flour should be 1:1 or Rice Flour should totally substitute Gram Flour.