Cut chicken and marinate with any masala you want on it.
Heat oil in a pan.
Cook the chicken with the onions, the other vegetables, salt and spices.
Blend cashew and milk into a paste.
Heat oil in another pan or a kadai.
Add ginger-garlic paste, tomato puree, chillies and coriander leaves.
Cook for 3 mins.
Add garam masala powder and mix well to get a thick paste.
When the chicken is done, add the above paste on top of the chicken.
Add the cashew milk paste to the chicken.
Cook for around 15 - 25 mins.
Add salt, chilly and water to smooth it out.