Place half the cherries, red wine,sugar, star anise and peppercorns in a pot and bring to boil. Turn down to a simmer for an hour. Strain liquid, discarding star anise and peppercorns. Press juice from cooked cherries and chop up. Reduce liquid by a third and pour, hot, over remaining pitted cherries. Cool before use. The cherries will keep in the refrigerator, in a sealed container, for two weeks. To serve, arrange panettone pieces into individual serving dishes. Place some chopped cherries on panettone, scoop gelato on and then spoon some whole cherries and their reduced syrup over the lot.