Chef Chuck Richardson set up his portable kitchen outside One Independent Square Wednesday to promote his creation, “The Cheesy Shrimp Sandwich.” Richardson said that since Philadelphia has the cheese steak, Memphis has barbecue and Chicago has the hot dog, Jacksonville should have a signature sandwich, too. Also called a “P.O.S.” or pocket of shrimp, it’s a combination of fresh local shrimp sauteed in olive oil with mushrooms, peppers, onions and cheese served in pita bread. The event was also a holiday fundraiser for the Mandarin Food Bank, Richardson said.