Delia has a marvellous recipe for a cherry sauce for duck, from her Winter Collection book ::::
Dried sour cherries
Morello Cherry Jam
Red wine
Basically, soak the dried cherries in a large glass of red wine over night. Dissolve the Morello Cherry Jam in some wine in a small saucepan. The higher the fruit contents the better the jam. If it says Preserve rather than Jam on the label, than all the better. Add the dried cherries to the pan and reduce somewhat. Pour over the duck.
Sour cherries are not terribly easy to find but Sainsburys and Morrisons have them, in the home baking section. I add a glass of ruby Port along with the red wine and its even better!