To prepare the whole duck, fold the neck flap over and secure with a cocktail stick.
Place the onion, ginger and lemon into the cavity and close with a cocktail stick or small skewer.
Score the duck breast.
Rub salt over the duck.
Place the duck into a large roasting tray and pour over about 2 litres of boiling water.
Leave for 4 minutes until the skin has tightened.
Discard the water and pat the duck dry and place back into the fridge, uncovered for 4 hours. You can leave it overnight as well.
Preheat the oven to 200°C/fan 180°C/gas 6.
Combine all the ingredients for the glaze together and spoon onto the duck generously.
Place on a rack / trivet on a roasting tray and roast for ½ hour.
Brush more glaze on and lower the temperature to 180°C/fan 160°C/gas 4 and roast for a further 50 minutes. Pour the duck fat into a container for later use.
Place the bunches of grapes into a piece of foil, pour over the sherry and wrap up.
Place them into the roasting tray and cook for about 8 minutes. They should be slightly cooked / roasted.
To check that the duck is done, insert a thermometer in the thickest part and the reading should be 75°C.
Cover and leave to rest for 15 minutes.
Arrange on a serving platter, garnish with sprigs of bay leaves around the platter and add the roasted grapes in bunches around the duck.
Serve with roasted potatoes, glazed carrots and pickled red onion.
Note: tuck the wings in when placing on the serving platter.
Serves 4 to 6