Dan Coudreaut studied at the Culinary Institute of America, the country's premier cooking school. He worked at restaurants in New York, then moved to Dallas, where he rose to lead kitchens at Cafe Pacific and the Four Seasons. At his latest gig, Coudreaut said, his favorite food is the fries, though it's a tough call because he also likes the oatmeal, the smoothies and the chicken nuggets. For eight years, now, he has worked for McDonald's as executive chef. His other title there is director of culinary innovation for the company's U.S. restaurants, which means Coudreaut's vision for what fast food should be influences meals for an estimated 27 million...