It's said to have taken off on Kolkata's streets during World War II, when Bihari migrant workers started selling spiced puffed rice to the British soldiers and American GIs flooding the wartime city.
Puffed rice is tossed by hand with mustard oil, chopped onion, tomato, boiled potato, roasted peanuts, and a mix of spice powders, mixed to order in a large bowl and served in a twisted paper cone. Vendors carry it in baskets through Kolkata's streets, parks, and train compartments.