Slice the potatoes into half-inch rounds, then dice these further into small, evenly-sized cubes.
Using a wok or other non-stick pan, take the minimum amount of oil needed and fry these cubed potatoes over a high heat to start with and then turn the heat down and cover. When the potatoes are a little more than half done, add the turmeric, chili powder and some salt, closely followed by the remaining spices. Stir to combine and put the lid back on once again.
When the potatoes are nearly ready (and you will have to be vigilant to ensure they don't get too soft), take the lid off, turn the heat up and stir-fry to enable any excess liquid to evaporate. Garnish with fresh cilantro and serve.