Braising chicken and greens together in a skillet does wonderful things to both bird and vegetables. As the chicken cooks, the skin browns, crisps and renders savory fat, which suffuses the greens with flavor. The greens, in turn, make a soft, moist bed on which to cook the chicken, keeping the meat supremely tender. In the end, the silky greens make a rich, mineral contrast to the juicy meat, while lemon juice and olives add brightness and acidity to the mix, giving it a needed jolt. Serve this with crusty bread or mashed potatoes to catch all the juices.