In a big bowl mix up all the ingredients of marinade and add chicken in that. Rub the marinade on the chicken and and cover it , keep it for 5 minutes.
Pre heat the oven and grill these chicken pieces for 20 minutes on 200C.
From this step you can Makhani gravy base (recipe in recipe note) or make a fresh makhani masala paste as given below.
In a Thick bottomed pan or kadahi, even a dutch oven works, heat 2 tablespoon of butter.
Add ½ inch pc of ginger and ¼ inch piece of cinnamon stick. Now add quartered onion, green chilli and cook on slow heat for 2-3 minutes till onion become translucent.
Add quartered tomatoes, 8 pc of cashew add salt and cook for 5-6 minutes till tomatoes are softened. Cool the mixture slightly and blend it to a smooth paste.
Add ½ tablespoon butter to the pan and return the pureed paste to the pan. Cook for 2-3 minutes and add kashmiri red chilli powder, ¼ teaspoon turmeric powder and add 2 tablespoon of tomato puree and 3-4 tablespoon water in the pan.
Add grilled pieces of chicken in this masala and mix chicken in makhani masala. Add 2 cups of milk little by little while stirring up all the time.
Mix well and add crushed kasuri methi sprinkle fresh chopped coriander leaves and serve with Nan or steamed rice.