Ah, gyros. The giant cones of rotating meat (pronounced YEE-ros, which is Greek for “spin”) have been a staple at Greek restaurants and take-out stands. But where do they come from? The meat’s uniform shape and source has been a mystery? until now. Intrepid New York Times reporter David Segal tracked down the origins of the U.S. version of the Greek treat in a factory in Chicago. He joins us now with his report.