A wonderful burger that shows what can result from thinking just a little bit differently. Choose the best-quality lean meat you can, be brave and have fun experimenting with combinations of ingredients.
Heat the oil in a frying pan and cook the onions on a medium heat, stirring frequently, until softened and slightly coloured. The small amount of oil used in this recipe means the onions might stick to the pan at some point; add a splash of water if necessary.
Add the ginger, garlic and green chilli and continue to fry until cooked and any liquid has evaporated. Transfer the mixture to a plate, spread out and allow to cool.
Preheat the oven to 200C/400F/Gas 6. Bring a large pan of salted water to the boil and add the potato wedges. Boil for 5-6 minutes, then drain. Place the parboiled potatoes on a baking tray, drizzle with the oil, then toss to coat. Put the tray in the oven and roast for 20-25 minutes, or until golden and crisp.
Mix the ingredients for the spice blend together in a small bowl and set aside until you serve.
Put the minced beef in a mixing bowl, add the onion mixture and all of the remaining ingredients, and mix well. (Mixing makes the meat more malleable and smoother; the more you work it, it the smoother it gets.) Shape into four to six burgers.
Heat a griddle pan, hot plate, frying pan or barbecue to hot. Brush the burgers with a little oil and cook: four minutes each side for a medium finish for six burgers, a little longer if you have made four larger burgers.
Rest the burgers for a few minutes while you sprinkle the cooked potato wedges with the spice blend. Serve the burgers in buns, with the wedges alongside and some ketchup for dipping.
If you don't have mango powder, you could add a splash of lemon or lime juice at the end for the potato wedges.