Green peppercorns are really unripe black peppercorns.They have a fresher flavour than their black counterparts. Green Peppercorns in brine are most famously used in the sauce for Steak au Poivre. They are a delicious addition to the preparation of sausages and terrines. They make an aromatic addition to the liquid used for steaming mussels and are also excellent for use in vinaigrette.