Prepare Aloo Filling: Boil the potatoes in salted water with a generous pinch of salt until tender, then drain well and return them to the pot along with the rest of the ingredients. Mash and mix well.
Fry Puris: Heat the oil to 180°C (356°F) and fry the puris for 3-4 minutes or until they have puffed up and turned golden brown.
Assemble Pani Puri: Make a hole in the puris, add a teaspoon of the potato filling, then dip into the sauce of your choice.