In a large bowl, whisk together 6 tablespoons gram flour (besan), 3 1/2 tablespoons rice flour, 1/4 teaspoon salt, 1/4 teaspoon turmeric powder, 3/4 teaspoon red chili powder, and 3/4 teaspoon garam masala powder until evenly combined.
Stir in 2 teaspoons ginger-garlic paste, 1/3 cup finely chopped onion (if using), 2 chopped green chilies (if using), 1 tablespoon lime juice, and 2 sprigs curry leaves or 2 tablespoons chopped cilantro (whichever option you chose).
Lightly beat the 1 egg white in a small bowl, then add it to the flour-spice mixture. Add the 1/2 pound boneless chicken (cut into thin strips or bite-size cubes) and mix until the chicken is evenly coated with the dry mixture.
Gradually add about 2 tablespoons water (add as needed), stirring until you have a thick, stiff batter that clings to the chicken pieces without running off.
Pour enough oil for deep frying into a deep pan and heat over medium heat. Test the oil by dropping a small blob of batter into it — it should sizzle gently and rise to the surface.
Fry the coated chicken pieces in small batches to avoid crowding the pan, turning as needed, until they are golden brown and cooked through (no pink inside).
Use a slotted spoon to transfer the fried pakoras to paper towels to drain excess oil.
Serve hot, garnished with fresh chopped cilantro.