The smoke rising from Babitha Sivadasan’s kitchen in rural Kerala carries a scent that belongs to her grandmother’s era.“I have started cooking with firewood,” said Babitha, who began rationing her half-empty cooking gas cylinder after failing to secure a refill from her Indian Oil distributor. “The agency hasn’t taken bookings in a week.”As the Iran war enters the third week and cooking gas becomes scarce amid a conflict-driven supply shock, some Indian homemakers are turning to practices of...