Heat a couple of inches of vegetable oil in a wide saucepan or wok.
Add the potatoes and fry over a medium heat, turning occasionally, until they are just soft in the centre when tested with the point of a sharp knife. This should take about 10-15 minutes. They should be fairly pale in colour.
Remove the potatoes from the oil and drain on kitchen paper for five minutes. Once cool enough to handle, using the palm of your hand, gently flatten the potatoes as much as possible without them losing their shape.
Before serving, reheat the oil. Add the potatoes to the hot oil and fry over a low-medium heat for about 5-6 minutes, until the potatoes are golden and crisp.
Drain the potatoes, then sprinkle over the salt and spices and serve.