Soak cashews in half cup hot water until needed later.
To a mixing bowl add Greek yogurt (hung curd), salt, black pepper, ginger garlic paste, kasuri methi, coriander powder and garam masala.
Mix well and taste test to adjust salt and spice. Add the chicken and marinate. Cover and set aside at least for 30 minutes to overnight in the refrigerator.
Heat oil in a pan. Add cardamoms, sliced onions, ginger and garlic. Saute until transparent for about 4 to 5 mins. Do not brown them.
Cool down and add them to a grinder jar along with cashews and milk/cream (added in 2 batches if needed). Grind to a smooth puree.
Pour half of the ghee to a pan & heat it on a low flame. Add all the optional ingredients - chopped green chili, cloves, black cardamom, cinnamon and mace. Be careful, the spices can splutter.
Pour the blended mixture along with water. Bring it to a gentle boil on a medium heat. Cook covered until thick & you see specks of oil/fats on top. This takes about 12 to 13 minutes. Keep stirring every 5 mins.
While the gravy simmers, heat a pan with the rest of the ghee and place the chicken pieces. Fry them until almost cooked, for 3 mins on each side.
It’s okay if the chicken is undercooked, if you want you may brown the chicken.
When the sauce is thick, stir in the garam masala, nutmeg, salt, kasuri methi, black pepper and the pan-fried chicken.
Cover and cook for 2 to 3 mins. Taste test and adjust salt and more black pepper or garam masala. If you want you may add heavy cream.
Garnish with black pepper. Serve Malai chicken with Tandoori roti, Naan, Yellow rice or Saffron rice. If you want you may squeeze some lemon juice before serving.