Boil the jaggery and tamarind in a cup of hot water until the mixture thickens slightly. Keep it aside.
Mix the green chilies and mint leaves. Grind to a smooth paste. Keep it aside.
Take the chopped potatoes in a bowl and toss it with chaat masala and salt. Keep it aside.
Put the puffed rice in a large bowl and add mint leaves paste.
Add chopped onions, tamarind water, sev, green chilies potatoes and mix well.
Garnish with coriander leaves.
Bhel Puri is ready to serve.