Like all citrus fruits, blood oranges are a great source of vitamin C and fiber. But you may not have known that their red pigment, anthocyanin, is a strong antioxidant.
In a small bowl, combine vinegar, orange juice, mustard, and oil, whisking well. Whisk in salt and pepper.
In a large bowl, combine shredded duck, salad greens, hazelnuts, and orange sections. Drizzle with vinaigrette; serve.