- Peel the potatoes and cut into 3/4 inch thick pieces. Place in a saucepan, cover with water and boil for 10-15 minutes. Drain well, mash and leave to cool.
- Heat 2 tsp of oil, fry the leeks, garlic and 1 slice of chopped ginger for 2-3 minutes.
- Stir the leek mixture into potato with sweetcorn, seasoning and yogurt. Shape into 8 patties and toss in flour to coat on both sides. Chill for 30 minutes.
- Preheat the grill to medium. Place the patties on a grill rack and lightly brush with oil. Grill for 5 minutes then turn over. Brush with oil and grill for further 5 minutes, until golden. Drain on kitchen paper.
- To make the sauce, place vinegar, sugar, chili and ginger cut into a strips in a pan. Bring to boil and simmer for 5 minutes. Stir in the wine white.
- Blend stock and cornstarch to from a paste then stir into the sauce. Heat through, stirring, until thickened.
- Transfer the patties to serving plates, spoon over the sauce and serve.