Dosa Potatoes

3 tablespoons ghee or vegetable oil
1 teaspoon mustard seeds
1/2 teaspoon cumin seeds
2 small dried hot red peppers
1 medium onion, diced
1/2 teaspoon salt
1/2 teaspoon turmeric
Pinch of asafetida
1 tablespoon grated ginger
6 to 8 curry leaves
4 garlic cloves, minced
2 small green chiles, finely chopped
1 1/2 pounds yellow-fleshed potatoes, such as Yukon Gold, boiled, peeled and cubed
1/2 cup roughly chopped cilantro, leaves and tender stems

Put ghee in a wide skillet over medium heat. When oil is wavy, add mustard seeds and cumin seeds. Wait for seeds to pop, about 1 minute, then add red peppers and onion. Cook, stirring until onions have softened, about 5 minutes. Season lightly with salt. Add turmeric, asafetida, ginger, curry leaves, garlic and green chile. Stir to coat and let sizzle for 1 minute.

Add potatoes and ½ cup water. Cook, stirring well to combine, until liquid has evaporated, about 5 minutes. Mash potatoes a bit with the back of a wooden spoon. Season well with salt, add cilantro, then set aside at room temperature. (Potato filling may be prepared up to a day in advance.)