Natural selection: Chipotle Mexican Grill CEO Steve Ells believes that improving ingredients, not changing the menu, will sustain the chain.(Interview)(Biography) From: Chain Leader | Date: July 1, 2006| Author: Farkas, David | COPYRIGHT 2006 Reed Business Information, Inc. (US). This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan.  All inquiries regarding rights should be directed to the Gale Group.Copyright information

With comparable-store sales growing by double digits, shares trading hands at $60 apiece and a market cap of nearly $2 billion, 505-unit Chipotle Mexican Grill looks like the real deal: a proven concept with plenty of staying power.

The 13-year-old company's track record helped double the stock price on its opening day in January, making it the second biggest gain in restaurant history (ill-fated Boston Market holds the record). The Denver-based company is using part of ...