1.Preheat oven to hot.
2.Quarter duck; discard all bones. Slice duck meat thickly, keeping skin intact; place on oven tray. Roast, uncovered, in hot oven about 10 minutes or until skin crisps; discard duck fat. Meanwhile, make hoisin dressing.
3.For hoisin dressing, Combine ingredients in small saucepan; bring to a boil. Reduce heat; simmer, uncovered, 2 minutes. Cool 10 minutes.
4.Heat oil in wok or large frying pan; stir-fry onion, choy sum and tat soi, in batches, until greens just wilt. Place mushrooms in same wok; stir-fry 2 minutes. Add the water; bring to a boil. Reduce heat; simmer, uncovered, about 2 minutes or until mushrooms soften.
5.Place duck, vegetable mixture and mushrooms in large bowl with dressing and snow peas; toss gently to combine. Divide sprouts among serving plates; top with salad, sprinkle with sesame seeds.