Prepare roast duck according to package directions. Cut around bone and slice.
Meanwhile, make salad dressing by mixing all ingredients in a bowl and mixing well.
In a large bowl, add spring salad mix, sliced mangoes, mandarin oranges, and sliced roast duck. Sprinkle green onions and sesame seeds over the salad.
Just before serving, give the salad dressing another good mix to make sure no sugar has settled to the bottom. Pour the salad dressing over the salad and toss to coat.