``Top Chef Masters'' returns for its fourth season with host Curtis Stone and returning judges James Oseland and Ruth Reichl. Also joining the judging panel this season are food journalist Krista Simmons and editor Francis Lam. This year's crop of guest judges includes such entertainment luminaries as former boxer Sugar Ray Leonard, Olympic gold medalist Brian Boitano and rock band the B-52s. This season pits 12 world-renowned chefs against one another in a competition based at The Cosmopolitan Las Vegas with chefs eliminated weekly until one remains, who earns the title of Top Chef Master and $100,000 for his or her chosen charity. Among the chefs competing are Art Smith, Oprah Winfrey's former personal chef who also competed in the show's first season, and Lorena Garcia, who worked as a judge alongside Stone on NBC's ``America's Next Great Restaurant.''