Add whole unpeeled potatoes to a large pan of cold salted water. Bring to the boil, reduce heat and simmer for about 35 minutes or until potatoes are tender.
Drain well and pat dry on kitchen paper. Cut potatoes in half if they are not tiny, and leave to cool slightly.
Heat oil in a hot wok until surface seems to shimmer slightly. Add potatoes and stir-fry for about 3 minutes or until lightly browned all over.
Add ginger and stir-fry for 30 seconds. Add sugar, wine and soy sauce and stir-fry for about 1 minute or until slightly caramelised. Serve immediately, sprinkled with Sichuan pepper and salt.