On a regular Sunday afternoon — when most people in Kolkata prefer a post-lunch siesta — Siddhartha Roy Burman and his wife quietly step out of their air-conditioned living room, and walk into one of Khadim’s many showrooms in the city. They give a pep talk to the staff, engage a customer in light conversation, or just observe how patrons behave in the store. They run the chain and despite its growth, refuse to let go of the family-run feel to it.