Take yogurt in a bowl. Add salt, chili powder, turmeric powder, ginger and garlic paste.
Mix and add to chicken. Marinate for half an hour or preferably overnight in the refrigerator.
Blend tomatoes, chilies, coriander, ginger, garlic and cashews with a little water to make a smooth paste. Keep aside.
Heat oil and add onions, sauté until golden brown. Add paste, red chili powder, coriander and cumin powders and tomato puree. Tomato puree gives vibrant red color to the gravy if the tomatoes are not red enough. It is, however, totally optional. Cook until moisture evaporates and oil separates from the gravy.
Add the marinated chicken. Stir fry on high heat until chicken turns white.
Add water, cover and cook until chicken is tender (approx. 25-30 minutes). Add more water if needed while cooking.
Restaurant Style Chicken Masala is ready. Sprinkle garam masala, green chilies and coriander leaves serve immediately.