Yann, found this one at http://www.bawarchi.com/cookbook/chats2.html. Closest I can find. I think chickpeas are in the papdi, or at least a quick google implies it.

Chatpati Chaat

1/2 cup boiled drained corn kernels
1 medium potato, boiled, peeled, diced
1 medium onion chopped
1/2 cup papdi or puris (refer) or cornflakes
2 green chillies minced fined
1 tsp. ginger grated
5-7 mint leaves finely chopped
1 tsp. coriander leaves finely chopped
2 tsp. lemon juice
1/2 tsp. chaat masala
1/2 tsp. sugar
salt to taste
1/4 tsp. white vinegar
1/2 tbsp. oil

Heat oil in heavy pan, add chillies, ginger, potatoes and toss for 2 minutes.
Allow to cool. Add all other ingredients and toss till well mixed.
Serve immediately accompanied with milk shakes, soft buns or crisp baked canapes.

Making time: 25 minutes
Makes: 4 servings
Shelflife: Best fresh