Preheat the oven to 190C/375F. Place a rack in a roasting tin. Prick the duck portions all over, sprinkle with salt and pepper.

Place on the rack and cook in the oven for 45-50 minutes, until the duck skin is crisp and the juices run clear when pricked with the point of a knife.

Meanwhile, simmer the lemon and orange rinds and juices together in a saucepan for 5 minutes.

Add the redcurrant jelly and stir until melted, then stir in the port. Bring to the boil and add mace or ginger and salt and pepper, to taste.

Transfer the duck to a serving plate; keep warm. Pour the fat from the roasting tin, leaving the cooking juices.

With the tin over a gentle heat, stir in the brandy, dislodge the sediment and bring to the boil. Stir in the port sauce and serve with the duck, garnish with orange slices.