1. Place sugar in a medium saucepan and set over medium-high heat. As sugar begins to melt, use a fork to gently stir sugar from edges to center of pan. Continue stirring in this manner until sugar is a deep amber color.

2. Remove caramel from heat and carefully stir in vinegar, orange zest and juice, chicken broth, and shallot. Return to medium-high heat and boil, stirring occasionally, until reduced to 2/3 cup, 20 to 25 minutes.

3. Score fat of duck breasts with the tip of a knife in a crosshatch pattern to form 1-inch diamonds. Season both sides of breasts with salt and pepper. Place breasts, fat side down, in a medium skillet and place over medium-high heat. Cook undisturbed until skin is crisp and golden brown, about 10 minutes. Flip and continue cooking to desired doneness, about 8 minutes more for medium-rare (125 degrees). Allow meat to rest 10 minutes before slicing and serving.

4. Add orange supremes to sauce and pour over sliced duck just before serving.