Defrost the bird if frozen. Remove the giblets. Reserve the liver for the Forcemeat Balls and place the rest of the giblets in the roasting pan, under the rack to give flavour to the sauce. Trim off the very tips of the wings and cut away and discard the oily preen glands situated on the parson's nose at the very end of the backbone.
Adjust the oven rack to one slot below the middle position. Preheat the oven to 190°C. Season the duck inside and outside with Seasoned Sea Salt and rub the skin with the potato flour, this together with the salt helps to crisp the skin. Prick the skin all over with the point of a cooks knife, a trussing needle or sharp braai fork to allow excess fat to drain out during roasting. Stuff the cavity with the orange quarters and thyme.
Tie the legs and wings with string so that they sit snugly against the body.
Place a roasting rack over a big oven roasting pan and pour 4 cups (1 litre) of boiling water into the pan. (The water will prevent oily smoke fumes in your oven).
Position the duck on the rack, breast side up. Roast, uncovered for 1½ hours until the skin is brown and crisp. Turn the oven down to 180°C. Now start basting with the Sticky Marinade. Cook and baste for a further 20 - 30 minutes until the bird is brown and shiny.
Remove the duck from the oven - tent lightly with foil or greaseproof paper and leave to rest for at least 10 minutes before carving.
Pour all the fat out of the pan, but retain any liquid and brown bits that remain. Put the pan on top of the stove over high heat. Add the water and Chicken Stock Powder. Scrape with a flat tipped wooden spoon to loosen all the tasty bits sticking to the pan. When the water has been reduced by approximately half, add ½ cup (125 ml) Sticky Marinade, frozen orange juice concentrate and sherry. Boil fast for approximately 3 minutes until the flavours have blended.
Adjust the thickness of the sauce with a mixture of potato flour and a little water.
To serve: Garnish duck with orange slices briefly dipped in the sauce. Do not pour the sauce over the duck but present it at the table for guests to help themselves.
How to carve the duck
Making in advance
The duck can be roasted the day before and the sauce made and refrigerated. On the day, put the duck back into oven at 180°C for 20 minutes, and reheat the sauce in the microwave.