Ashima Ganguli stands in the kitchen of a Central Square apartment, combining Rice Krispies and Planters peanuts and chopped red onion in a bowl. She adds salt, lemon juice, thin slices of green chili pepper, wishing there were mustard oil to pour into the mix. Ashima has been consuming this concoction throughout her pregnancy, a humble approximation of the snack sold for pennies on Calcutta sidewalks and on railway platforms throughout India, spilling from newspaper cones.