Heat your oven to 475°F.
To season the duck, combine 1 teaspoon of ground coriander and ½ teaspoon of ground cumin in a bowl. Season it with 1 teaspoon each of sea salt and freshly ground black pepper to taste. Sprinkle the coriander and cumin seasoning both outside and inside the cavity of the duck. Cut one half of an orange into 4 pieces and stuff the duck's cavity with the orange pieces, fresh herbs, and 4 slices of onion.
6 lb whole duck, 1 orange, 3 tablespoon fresh thyme leaves, 3 tablespoon fresh marjoram, 1 teaspoon ground coriander, ½ teaspoon ground cumin, Sea salt and freshly ground black pepper, 2 tablespoon fresh parsley
In a roasting pan, add the remaining onion, 1 chopped carrot, and 1 chopped celery stalk underneath the stuffed duck.
1 onion, 1 carrot, 1 celery stalk
Roast the stuffed duck for 30 minutes in the preheated oven.
Mix the juice from the remaining half of the orange with 1 cup of chicken or duck stock. Pour the mixture over the duck once the initial 30 minutes are done. Lower the temperature of the oven to 350°F. Cook the duck for another 1 ¼ hours, until the thermometer inserted into the thickest part of the thigh reads 170°F.
1 cup broth
Once fully cooked, remove the duck from the oven, and turn on the broiler. Then, place the duck on a new roasting pan and broil for 4 minutes. This should give the skin a golden brown texture. Place the cooked duck on a cutting board and let it rest for 15 minutes.
Remove the vegetables from the original roasting pan and strain the juices to remove unwanted bits of debris. Keep some of the fat. Add enough chicken or duck stock to the pan juices to obtain 1 cup of liquid, and pour it into a small saucepan. Add ⅓ cup of fresh orange juice, 2 tablespoons of apple cider vinegar, and 1 tablespoon of orange zest to the saucepan. Then, let the sauce simmer for about 5 minutes until it has thickened. If the sauce has not yet thickened to your liking, add back in 1 tablespoon of the skimmed-off duck fat and mix it in.
⅓ cup orange juice, 2 tablespoon apple cider vinegar, 4 tablespoon chicken or duck stock, 1 tablespoon orange zest
Serve the duck with the orange sauce. Remember, you can taste the dish and adjust it to your liking by adding more sea salt and freshly ground black pepper.