Put few gashes with knife all over the chicken.
Heat little oil in a pan.
Fry onion slices and cashews for 10 minutes or until they become golden in color.
Make a smooth paste with very little water.
In a mixing bowl, add that paste, yogurt, all of the spice powder, some salt, Kasuri methi, lemon juice and oil.
Mix very well and add the chicken legs.
Massage chicken legs with the marinade very well and keep in fridge for 4-5 hours or overnight.
Heat the butter in a pan, add the marinated chicken legs.
Fry for 10 minutes by covering the pan, chicken will release some juices.
Flip them over and cook until the chicken becomes soft and the gravy becomes dry.
If you want to cook them in oven, then preheat your oven for 10 minutes on highest temperature.
Then bake the legs for 15 minutes on 450 F and then flip them over and bake for another 15 minutes.
Brush them with butter.