FILE - In this Tuesday, Dec. 15, 2015, file photo, Chipotle Mexican Grill founder and CEO Steve Ells pauses for a moment during an interview with The Associated Press in a Chipotle restaurant in Seattle. The company said Wednesday, Nov. 29, 2017, that Ells will step down from the CEO position as soon as it finds a replacement. Ells will then become executive chairman. (AP Photo/Stephen Brashear, File)