Place the potatoes in a saucepan with enough water to cover. Bring to a boil, and cook 10 minutes, until tender. Drain and allow to cool slightly.
Heat the ghee in a large frypan over medium heat. Lightly toast the cumin seeds, mix in the green chillies and ginger. Season with chili powder and coriander. Stir in the potatoes, and cook about 5 minutes. Add the amchoor and salt, and continue cooking about 15 minutes. Garnish with the coriander to serve.