Preheat oven to 220°C. Combine the butternut wedges with the sweet rice wine and olive oil on an oven tray, toss to coat and roast for 20 minutes turning once, until golden and cooked through.
Meanwhile, for the caramelised plums, place the sugar in a saucepan over high heat and cook for 1-2 minutes until a light caramel starts to form.
Add the red wine vinegar (be careful as it will sizzle up) and cook gently to dissolve the caramel. Add the plums and cook for 1-2 minutes until the plums soften.
Heat the vegetable oil in a wok and stirfry the duck for 2-3 minutes.
Arrange the watercress, butternut and duck on plates, spoon over the caramelised plums, add the walnuts and drizzle with walnut oil to serve.Reprinted with permission of the SA Stone Fruit Producers' Association.