Make sauce: In a small saucepan, combine orange juice, chicken broth, and orange marmalade. Bring to a boil over high heat, and then lower heat and simmer for 15 minutes. If the mixture is too thin, then mix cornstarch with 2 tablespoons orange juice in a small bowl to make a slurry. Add slurry to sauce and briefly return to a boil. Keep warm until ready to serve.

While sauce is simmering, heat a grill or grill pan to medium-high heat. Sprinkle duck on both sides with paprika. Grill on both sides until medium-rare. Transfer duck to serving plates. Pour warm sauce over duck and serve.