Slice the duck thinly and place in a wide glass or ceramic bowl with the soy sauce, five-spice powder, crushed Szechuan peppercorns, garlic and ginger. Toss to mix well, cover and leave to marinate at room temperature for 20–30 minutes.
Spray a large nonstick wok or frying pan with cooking spray and heat over a high heat. Add the duck mixture and stir-fry for 5–6 minutes until browned but still pink in the centre. Transfer to a bowl, cover and keep warm.
Wipe the pan clean with kitchen paper, re-spray with cooking spray and heat over a medium-high heat. Add the ginger and chillies and stir-fry for 2–3 minutes. Add the cabbage and carrot and stir-fry for 3–4 minutes, or until the cabbage has softened. Stir in the soy sauce and shallots and continue to stir-fry for 1–2 minutes.
Transfer the stir-fried cabbage to warmed serving plates and divide the duck strips on top of each portion. Garnish with chopped coriander and serve.