Add all the ingredients to make green chutney in a blender jar and make a fine paste.
Next pour water just as needed and make a thick chutney. Set this aside.
Soak red chilies in very little hot water and set aside for some time.
When they soften add them to the blender along with garlic, salt and sugar.
Blend them together to make a fine paste adding water as needed. Set this aside.
Add tamarind, jaggery, red chili powder, cumin , coriander powder to very hot water and allow tamarind to soften.
Cool them completely and squeeze well. Pass this through a strainer.
Add ginger powder and salt. Add more water if needed to bring it to a consistency.
Place 6 to 7 papdis/ puri in individual serving plates.
Slice or crumble the boiled potatoes and place them on each of the papdis.
Add garlic chutney and then top with some onions.
Top some tamarind chutney and green chutney on each of the papdis.
Sprinkle some chaat masala.
Top with a generous amount of nylon sev.
Garnish with some finely chopped coriander leaves.
Serve sev puri immediately.