Preheat the oven to 250°F (120ºC). Season the duck with the five spice powder and salt.
Place the orange slices, ginger, garlic and star anise in a roasting pan, with the duck on top. Roast for 1½ to 2 hours, until the skin is golden brown and crispy. Remove from the oven and allow to rest on a wire rack until cool enough to handle. Carve the duck: cut the breast into ⅜ in thick (0.75 cm) slices, and pull the leg meat into bite-sized pieces. Set aside.
Soy & Ginger Vinaigrette
Whisk together all of the ingredients.
Duck Dressing
Whisk together all of the ingredients.
Crispy Duck Salad
Heat the canola oil to 350°F (175°C) in a pot large enough that it is not more than half full. Fry the sliced duck in batches until crispy, about 1 to 1½ minutes. Transfer to a large bowl, add the duck dressing and toss to coat.
Peel the carrot, daikon and beet, and cut into fine julienne strips or ribbons using a spiralizer. Mix with the watercress and toss with some of the soy and ginger vinaigrette. Divide between 6 serving plates. Top with crispy fried duck and garnish with crispy onions and sesame seeds.