Tandoori Chicken Marinade: Mix all marinade ingredients, coat chicken, and refrigerate for 50-60 minutes.
Butter Chicken Gravy: Caramelize onions, add ginger, garlic, tomatoes, and spices. Cook until thickened. Let it cool for 15-20 minutes.
Shredded Tandoori Chicken: Roast marinated chicken in a preheated oven, shred, and mix in the marinade. Cook for an additional 5-7 minutes.
Blended Gravy: Blend the cooled onion-tomato mix, return to the pan, add water, and simmer for 2-3 minutes.
Assembling: Add shredded chicken, kasoori methi, cream, remaining butter. Mix well and cook for 1-2 minutes. Serve hot.