Heat oil for deep frying in a deep saucepan over medium-high heat.

Fry pappadums, one at a time, and drain on an absorbent towel. While frying, gently press down on the pappadums with a spatula to make them flat.

To make the tomato onion mixture, combine together tomatoes, onions, green chilies and white vinegar in a large bowl. Season with salt.

To serve, top the pappadums with tomato mixture.

Sprinkle with chat masala. Garnish with coriander (cilantro) leaves.