In a wok, heat oil. Saute the sliced onions with a pinch of salt till soft. Allow to cool.
Puree the cooked onion along with the soaked cashew and water till smooth.
In a saucepan, melt the butter. Add the ginger and garlic paste and saute for a couple of minutes till the raw smell is gone.
Add the onion puree, turmeric, chilli powder and garam masala and cook for a couple of minutes.
Add the tomato puree and cook till oil floats on the top. Stir occasionally.
Add in the chicken and cook till the chicken is done.
Add in the cream and stir well till combined.
Finally sprinkle in the kasoori methi, and adjust salt. Switch off the flame.
Serve garnished with coriander leaves with rice, rotis or even bread... just tastes awesome!
Notes
In order to make it less rich, I sometimes skip one of them - the cashew paste or the cream. While having guest, we add both. Personally, I prefer adding the cream at the end, sometimes the cashew paste leaves bites which I don't like!