Grind together ingredients from ginger garlic - black pepper corns, with 1-2 tbsp water, into a fine paste.
Heat oil in a pan. Add sliced onions. Cook till it becomes golden brown colour. Add ground masala & curry leaves. Fry the masala till the oil appears. Add chopped tomatoes. Mix well & cook for 3-4 mins. Add cleaned chicken pieces & salt. Mix well and make sure that chicken pieces are coated well with masala. Add 2- 2.5 cups of water. Cover & cook till the chicken is almost done.
Add the cashew paste to 1 cup of water and pour to the curry. Mix well and bring it to a boil. Reduce the flame. Cook for a few more minutes & remove from fire. Garnish with fried small onions & curry leaves (optional)
Notes
The gravy tends to thicken in due course, so adjust the consistency of the curry accordingly. For cashew paste, soak around 10-12 cashews (you can adjust the qty as per your taste) in 3 tbsp hot water for 10 mins & grind to a smooth paste. I used coconut oil for this curry.