Stone the cherries with a cherry Stoner or, better, with a piece of wire, bent over (like a hairpin) and stuck in a cork. Melt the redcurrant jelly in a shallow pan, dilute with 5 tablespoons water and bring to the boil. Throw in the cherries, cover the pan and let it cook for 5 minutes over a high heat.
Take off the heat and remove the cherries from the syrup