Cut the chicken into 12 pieces, remove and discard the skin, and set the pieces aside.
To make the batter, put all the ingredients for the batter into a large bowl, add 150 ml / 1/4 pint (2/3 cup) water and mix well. The batter should be of coating consistency.
Add the chicken to the batter and turn until the pieces are evenly coated. Cover and allow to chill in the refrigerator for 2 1/2 hours.
Heat enough oil for deep-frying in a kadhai or deep, heavy-based pan to 180'C / 350”F, or until a cube of bread browns in 30 seconds, then reduce the heat.
Working in small batches, add the battered chicken and deep-fry for 2-3 minutes, or until golden brown and cooked. Remove with a slotted spoon and drain on kitchen paper (paper towels).
Sprinkle over the chaat masala and serve with lemon wedges.