As Strong As Soup

In the area around Amiens in the Somme they take rhubarb very seriously and this recipe is based (pretty loosely) on a dish from there. The sauce has a sweet and sour quality that's sharp enough to cut through the rich flavour of duck but it will also work very well with pork, goose or guinea fowl.   If you're using sweet, forced rhubarb such as the superb product from the Rhubarb Triangle in Yorkshire, then it won't need much (if any) sweetening. If in doubt, use the minimum amount of grenadine and add any necessary sweetening at the end.  Despite my sincere attempts to be lazy, I'm now reluctantly forced to admit that the very best grenadine is homemade. Unless you're obsessed with cocktails, though, you probably don't have any, so use whatever commercial brand you fancy. If you don't have any grenadine at all, then just sweeten with honey, agave nectar or even plain sugar, but combine them with a little pomegranate molasses, if possible. The sauce can be