Combine the cranberries, sugar and ginger (if using) in a large sauté pan; cook, stirring occasionally, over medium heat until sugar is melted and cranberries begin to pop, about 5 minutes.

Add 1 cup water, and simmer until liquid has thickened slightly, about 4 minutes. Some cranberries should still be whole. Remove from heat, and stir in oranges. Let cool before serving.