First, marinate the chicken with lemon juice, ginger and garlic paste with some rock salt and set it aside for half an hour. This will tenderize the chicken and ensure proper cooking.
Now, add all the spices, such as red chili powder, garam masala, Kasuri Methi, coriander powder, roasted cumin powder, Kashmiri red chili powder (for colour), black pepper, drained curd, rock salt if required, all-purpose flour (Maida), corn flour, and an egg. Mix it thoroughly.
Place a pan or kadai over a stove or clay stove. Add enough oil to come halfway up the chicken pieces (about 3-4 cm), and fill the pan no more than halfway for frying and heat it. Do not make the oil too hot; otherwise, the chicken will become overly crispy on the outside but undercooked inside. (Pro tip: I usually drop a pinch of batter in the oil. It should sizzle steadily, not violently, or the coating will burn before the inside cooks.)
Add the marinated chicken to the hot oil and fry it on medium heat. Repeat this process to fry all the chicken pieces. (Pro tip: I always fry in small batches because crowding drops the oil temperature and gives soggy, greasy chicken.)
Remove the chicken from the pan and set it aside. Heat the pan again, then add all the chicken pieces back into the pan to flash fry them. Remove them when done.
Your crispy fried chicken is ready.