This sprawling, sunny-orange restaurant brings eco-conscious fast-food eaters the goods they crave: burgers made with all-natural beef, no hormones or antibiotics, topped with cage-free organic eggs and nitrate-free bacon; preservative-free buns; vanilla-bean-speckled milkshakes; and no petroleum-based packaging. The loud music and flat-screen TVs draw a student crowd from the surrounding college campuses in the South Loop.