In a bowl mix together the chicken with the marinade ingredients
Brown the chicken and remove from pan when cooked
Add onion and a pinch of salt and cook till softened
Add tomato, garlic and optional cashews
Add sugar, salt, Kashmiri chilli powder and garam masala
Add water, cover and cook on low until tomatoes have softened
Place the sauce in a blender and blend until smooth
Return the sauce to the pan and start to reheat
Add butter, cream and kasuri methi
Simmer for 5 minutes and finish with chopped cilantro