The British quick-service restaurant chain Pret A Manger is expanding its American empire and planning to open a location in Boston, which would be the company's fourth U.S. city. That news comes via Eater Chicago, who recently saw its fifth Pret A Manger open. What exactly is a Pret A Manger? The chain was born in London in 1986 and serves sandwiches, salads and wraps using "natural, preservative-free, ethically-sourced ingredients." The company boasts that it has no use for a "sell-by" date as whatever doesn't sell each day goes to charity. The new Boston shop will join 294 locations worldwide including others in Hong Kong and France.