Peel and boil the potatoes—then cut them into ¾-inch pieces.
Pour the oil into a heavy bottomed pan, set the heat to medium high, and heat until almost smoking.
Add the cumin seeds and cook until they begin popping—approximately 10–seconds. Adjust the heat as required to avoid burning the seeds.
Add the ground cumin, chili powder, turmeric, and amchur to the oil and cook for several seconds.
Add the potatoes and mix thoroughly.
Add the salt and pepper and continue cooking until the potatoes are light golden brown.
Sprinkle with cilantro and serve.