Chop the potatoes into tiny cubs and cook them in a microwave, once done sprinkle with salt and red chilli powder and keep aside.
Take each puri and gently make a large hole on the top side with your index finger or thumb for stuffing. Stuff it with some Kala chana, potatoes, onion and sev over it.
Drizzle some khajur ambli chutney and mint water.