There were times when the simplest American product inspired near hysteria in Eastern Europe—be it stonewashed 501s or freshly pressed pop records. Those days are long gone, except for a little corner of Mokotów, where the basic burger is causing a ruckus. Since opening in the spring of 2012, queues may have eased but the quality stays the same. A straight-up delivery of Polish beef, Irish cheddar and fresh buns hits all the right notes, so that after the Burger Bar, you won’t have to sing for your supper.