Grind the coriander leaves, mint leaves, green chilies and garlic with required quantity of water to a fine paste. Add lime juice and mix well.
Soak the tamarind in water and strain the pulp. Add 3-4 cups water. To it add 2 tbsp. of the mint paste, salt and all the powdered spices. Mix well. Adjust seasoning and keep aside. Add the boondi while serving.
For the sweet tamarind chutney - In a bowl, mix together tamarind paste, 1/2 cup water or as required, salt, sugar and red chilli powder. keep aside.
In a bowl, mix together mashed potato, boiled chana, salt, coriander leaves, red chilli flakes, pepper powder, roasted cumin powder and lime juice.
To serve, make a hollow in the centre of the pani puris with your spoon. Stuff a little of the filling and drizzle a tsp. of the sweet chutney over it. Pour some of the pani puri water and gulp it down immediately at a go.
