Bring to a boil over high heat, reduce the heat to low and cover the pan partially. Simmer gently, stirring occasionally, until the sauce thickens, the apple is tender and the cranberries have burst, 10 to 15 minutes.
07Transfer the cranberry sauce to a heatproof bowl and let cool for 1 hour before serving. Or cover and refrigerate; bring to room temperature before serving. Transfer the cranberry sauce to a sauce boat and pass at the table.