Step 1Heat the oil in a small saucepan over medium-low heat. Add the mustard seeds, cumin seeds, asafetida, turmeric, ginger and curry leaves and stir. Cook for several minutes, until the spices release fragrance and the seeds start to pop.
Step 2Add the potatoes and mix well. Add the water and salt to taste. Raise the heat to medium, bring to a boil, then reduce heat to simmer. Cover and cook until the potatoes are done, about 12 minutes.
Step 3Sprinkle with the coriander and cumin and mix well. Garnish with the cilantro, and serve hot with warm Indian bread (nan) for dipping.