Not your average rice ball by any stretch

Every year during spring, Shanghainese people brave long queues to get their hands on a special green snack that is steeped in history and tradition

It is 10 pm, and the shops along Nanjing Road West are about to close for the day, with the exception of the kitchen in Wang JiaSha, located in a five-story glass and steel building in the middle of Shanghai's famous shopping street.

Here, a handful of white-robed pastry chefs have just started their overnight shift. But Wang JiaSha is not a supper joint, and it will not be serving any customers through the night.