Heat oil in a pot or handi until hot. Add onions and fry until they are golden brown to transparent. Add in the chicken pieces and stir for 3-4 mins.
Add in ginger paste, garlic paste, tomato, green chillies, and cashewnut paste; stir for a few minutes.
Add red chilli powder, turmeric powder, coriander powder, butter, and salt to taste. Add some water as required.
Cover and cook on low heat until the chicken is well done.
Garnish with coriander/cilantro leaves and mix.