Marinate the chicken pieces with little bit of turmeric powder, chili powder, coriander powder, lemon juice and salt for 10 to 15 minutes.
Heat some oil in a deep pan. Saute the chopped ginger, garlic, green chillies and curry leaves.
Add the sliced red onions and saute until it is pinkish. Now add the rest of the turmeric powder, chilli powder, coriander powder, chicken masala, chopped tomatoes and saute well until all the spices blend in.
Add the marinated chicken pieces and mix well. Cover and let it cook on a slow fire for 6-7 minutes.