Pre-heat the oven to 100 degrees celsius. Mix together the salt and juice in a casserole dish that is large enough to hold the thighs and the brine and is also ovenproof, and add the duck thighs, spices and rosemary sprigs. Bring to the boil on the top of the cooker, cover with the lid and then continue baking in the oven for three to four hours. The duck thighs will then be preserved and will keep for several weeks in the brine.
When serving, lift the thighs out of the brine, allow the brine to run off and sauté them in butter or oil until the skin is crispy and the meat has been heated through.
Light a BBQ grill.
Cut a checked pattern in the layer of fat on each breast. Season with salt and pepper. Lay one sprig of rosemary on the meaty side of each breast and start grilling with the meaty side facing downwards in order to prevent it from catching fire. Turn when the meat is nice and brown. Grill the fatty side until it is crispy and golden brown.
Allow the meat to rest on one side of the BBQ for a few minutes. Grill the meat once more until it is medium rare. Use an oven thermometer to check that the core temperature is approximately 60 degrees celsius. Put on one side for a few minutes. Cut the meat into thin slices.
Cut the apples in two and place on the BBQ. Grill until they are golden brown and slighty soft.
Serve the duck thighs with the apples and duck breast.