In a bowl mix together 1/2 cup yogurt, 1/2 cup milk, salt, and 1 tbsp black pepper. Marinate chicken pieces in it for 3 to 4 hours or even overnight. (you can add more yogurt and milk if needed)
In another small bowl mix together 1 egg white and 1/2 cup milk.
In a large tray or bowl mix together 2 cups plain flour, 1 tbsp cornflour, 1 tsp garlic powder, 1 tsp onion powder, 1 tbsp red chili powder, 1/2 tsp garam masala powder, 1/2 tsp dried oregano, 1 tbsp brown sugar, 1 tbsp black pepper powder and salt.
Heat cooking oil in a large wok for deep frying.
Remove chicken pieces from the marinade and roll each piece into the plain flour-spice mixture first, and then dip into egg white – milk mixture and then again into the plain flour-spice mixture.
Once the oil is hot, reduce the flame to medium and fry chicken pieces one by one. Do not overcrowd the wok.
Fry chicken pieces for about 12 to 15 minutes (12 minutes for small pieces).
Remove the pieces and place them on a wire rack for the excess oil to drain out.
Serve hot.