Overview: Greens & Gravy (Atlanta, Ga.) • Boteco (Austin, Tex.) • Porter's Real Barbecue (Richland, Wash.) This trip, Guy Fieri digs into Southern comfort food and South American specialties. In Atlanta, a real-deal soul food spot dishing out collard green lasagna and a twist on fried chicken. In Austin, a food truck putting out Brazilian flavors that has some A-list fans. And in Richland, Washington, a joint going big with their legit barbecue.