Mix together onions, tomatoes, chilies, coriander leaves, salt, chaat masala, chilli powder, lemon juice or tamarind chutney. If you do not have tamarind chutney, then chop the dates very finely and add to the other ingredients.
Mash and mix together all the ingredients. Rest just for a few minutes to release some moisture.
Add cornflakes and mix everything well.
If needed sprinkle some lemon juice or chaat masala. Sprinkle some peanuts over the cornflakes chaat and serve immediately.
If using hot ghee, add cumin powder to the chaat first and pour warm ghee pver the powder. Toss everything well.