Squeeze the papaya till the water drain out. Transfer the papaya into a plate, add mashed potatoes and spices. Mix well.
Divide the mixture into 16 equal portions and roll each portion into a bowl. Keep aside.
Heat the oil in a deep non-stick pan and deep fry these koftas in kadai on a medium flame till to golden brown from all the sides. Remove from the oil and keep aside.
Take a mixer jar, add chopped onion, chopped tomatoes, green chilies, ginger paste, cashew nuts and grind together till to smooth paste.
Add oil in a nonstick pan, add cumin seeds. When the seeds crackle, add onion tomato paste and saute on a medium flame for 5 minutes.
Add the coriander powder, chilli powder and turmeric powder, mix well and cook on a medium flame for 2 minutes, while stirring occasionally.
Add cream, garam masala, salt and 1/4 Cup water, mix well.
Cook on a medium flame for 3 to 4 minutes, while stirring occasionally. Now gravy is ready to serve.
Add koftas and mix gently and cook on a medium flame and garnish with cream and coriander leaves. Serve hot with tandori breads.