Place the chicken pieces in a large bowl. Pat dry to remove any moisture.
Add all the ingredients listed under chicken pakora marination.
Mix until the chicken pieces are well coated with the spices and herbs.
Cover the bowl and set it aside for 30 minutes.
Add one beaten egg white, besan, and rice flour or cornstarch, mix well.
If it looks too dry, add a few tablespoons of water at a time and mix well. I added only about 2 tablespoons of water.
Heat oil for deep frying in a wok or kadai over medium heat.
Test the temperature of the oil with a candy or deep-frying thermometer (it should register 350° F/180° C). You can also test the oil temperature by dropping a little of the batter into the hot oil. It must rise to the surface slowly. That means the oil is ready for deep frying.
Slide the chicken pieces gently in the hot oil. Leave it undisturbed for a minute.
After about a minute, flip the pieces with a slotted spoon and continue frying until the chicken is cooked through and turns a golden brown on all sides, about 3-4 minutes (depends on the size of your chicken pieces). If using bone-in chicken, it will take a few minutes longer.
Transfer the chicken pakora to a plate lined with an absorbent paper napkin or on a wire rack to drain off excess oil. Continue frying the rest of the chicken pieces in the same way.
The last step is to deep-fry the green chilies, slit lengthwise (very important to use only slit green chilies or peppers) and curry leaves, until they turn crispy, about 30 seconds.
Drain and add it over the chicken pakoras.
Sprinkle chaat masala and serve immediately.