Put the fish fillets in a bowl, add hung curd, green chilli paste, mint leaves paste, cumin powder, black pepper powder, poppy seed paste, cashew nut paste, mustard paste, lemon juice, salt as per taste, and fresh cream as per the quantity mentioned in the ingredients list. Mix all the ingredients well.
Place a burnt charcoal in the middle of the mixture on a small glass bowl, pour some ghee over it and cover the lid. This will give a burnt charcoal flavor to the kebab. Let the mixture marinate for ½ hour.