Add oil, salt and carom seeds in all purpose flour and make a fine dough. Keep it aside for few minutes.

Take a wok and heat 1 tablespoon oil crackle cumin seeds, then add asafoetida, fenugreek seeds, coriander seeds, ginger, green chillies and onion. Saute till soften

Now add gram flour, red chilli powder, dried mango powder, garam masala and mashed potato. Add salt. When roasted add little chopped onion and mint.

Now make a big puri from the dough, and cut it into two equal round shape with the help of biscuit cutter or katori.

Take one round puri and fill the center with the onion mixture and cover it with another. Press the corners with the help of fork.

Gently fry them on medium flame.

Serve hot.