I borrowed this method and these ingredients from a classic chicken recipe often made during the wine harvest with big bunches of red wine grapes. As the bird steams and braises in a terra-cotta roaster or Dutch oven, it releases its own fat and juices that make a rich sauce with the roasted grapes and shallots. Because it's made in one pot and results in tender, juicy meat every time, this is a perfect duck dish for beginners. Choose the darkest, plumpest grapes you can find such as Concord or muscat. Serve with crusty bread, la cruchade, or creamy potato purée.