The key to great duck is rendering the fat. To do that you must cut the fat side of the duck crossways, up and down. Season both sides of the duck with a seasoning of your choice. Then, in a cast iron skillet, over medium to high heat cook the duck fat side down. When the fat side is crispy and the fat rendered turn over the duck and finish cooking in a 350°F oven.

Duck is best served medium to medium rare so I remove the duck when the internal temperature reaches 130°F. Let the duck sit for 5-10 minutes before cutting. Consider saving the duck fat that accumulated in the skillet. It is very tasty and can be used in other recipes.

Drain off the duck fat from the skillet. Add the shallot and garlic to the skillet and soften over low heat. Next add in the vinegar and sugar. Melt the sugar while stirring. When the sugar darkens add in the orange juice and chicken stock. Hold back about 2 Tbsp of chicken stock. Bring to a simmer.

Continue simmering until liquid is reduced in half, about 15 minutes. You can add Grand Marnier, which is an orange liquor, but this is optional. In a small cup mix cornstarch with the 2 Tbsp of chicken stock to make a slurry. Add the cornstarch slurry to the skillet and stir in to thicken. Finally stir in butter to finish the sauce.

I find the best way to supreme an orange is to first cut the ends off an orange so it sits nicely. Then using a sharp knife cut the skin off by slicing from the top down. When all the skin is removed hold the orange on its side and section it by cutting on both sides of the membrane.