Mix all the ingredients (except chicken) for the marinade in a bowl. Taste it, adjust flavour if needed.
Add chicken and coat it in the marinade fully. Let it rest for few hours (1-2 hours at least).
Grill the chicken on stove top with butter.
For the gravy, add oil to a pan.
Add cashew nuts and roast till they are light brown.
Add onions and cook till translucent.
Add the ginger-garlic paste and cook till the raw smell fades.
Add the tomatoes and cook till oil separates/gets mushy.
Let it cool down and then blend to a paste.
To finish the sabzi, add butter to a pan.
Add the whole spices (cumin, cinnamon, cardamom, clove) and cook till it sizzles.
Add onions, ginger-garlic paste and green chilli slits and cook.
Add tomato ketchup/sugar and all the dry spices except garam masala and kasuri methi.
Mix well and let it cool for 2-3 min.
Add cream (or butter and milk) and mix well.
Add kasuri methi and garam masala.
Add the chicken pieces and cook for a minute.
Serve hot with rice/paratha/naan!
