Step 1

Cut potatoes into julienne on a mandolin, placing them in a bowl of cold water as you go to prevent them going brown. Set aside to soak to remove starch (30 minutes).

Step 2

Meanwhile, heat oils in a wok or frying pan over medium-high heat until shimmering, add ginger, garlic and chilli and stir-fry until fragrant (1 minute). Remove from heat, set aside to cool slightly, then add soy sauce and half the vinegar and set aside.

Step 3

Drain potato, rinse, then add to a saucepan of boiling salted water over medium-high heat, bring back to the boil, then cook for 1 minute. Drain well, transfer to a large bowl, add stock and remaining vinegar and stir to coat well. Set aside to cool, then transfer to serving bowls. Drizzle with ginger-chili dressing, scatter with spring onion and serve.