Heat oil in a pressure cooker or kadai, add corn and mix. Cover with the lid on and let the corn pop.

Chop cucumber and tomato finely. Finely chop mint leaves.

When all the corn has popped put them into a large mixing bowl. Add cucumber, tomato, mint leaves, red chilli powder, green chilies, chaat masala and little salt. Squeeze the juice of lemon and mix well.