Place chicken in a pan. Add turmeric powder. Season with salt. Cover with water. Bring to boil. Cover and cook for 5-7 minutes or until chicken is cooked through. Remove chicken from the pan. Set aside to cool slightly. Reserve the liquid. When chicken is cool enough to touch, shred and set aside.
Alternatively, you can cook chicken in a pressure cooker for 3 whistles.
To make ginger garlic paste, place ginger ad garlic in a food processor. Process to a smooth paste. Set aside.
To make spicy shredded chicken, heat oil in a frying pan over high heat. Add onions, green chilies and curry leaves. Sauté, stirring occasionally, for 2-3 minutes or until the onions are browned. Add tomatoes. Cook, stirring occasionally, for 2-3 minutes or until they turn mushy.
Add turmeric powder, coriander powder, garam masala and red chili powder. Season with salt. Sauté, stirring constantly, for a minute. Add shredded chicken. Add a little of the reserved liquid. Stir to combine. Cook for 3 minutes.
Stir in pepper powder and coriander (cilantro) leaves. Heat through. Garnish with chopped coriander (cilantro) leaves if you like.