To make the gravy, heat oil in a non-stick pan. Add cinnamon, green cardamoms, black peppercorns and cumin seeds and saute till fragrant.
Add red pumpkin, bottle gourd, red chilli powder, coriander powder, turmeric powder, cumin powder and garam masala powder and mix well.
Add bhuna masala and mix well. Add coriander and mint leaves and mix. Transfer the mixture into a mixer jar and let it cool slightly. Add a little water and grind into a puree. Transfer the puree into a bowl and set aside.
To make the koftas, mix together mixed vegetables, potatoes, breadcrumbs, green chillies, ginger, red chilli powder and salt.
Heat sufficient oil in a kadai. Divide the mixture into equal portions and shape them into balls. Slide these into hot oil and deep fry till golden and crisp. Drain on absorbent paper.
Heat butter in another non-stick pan. Add tomato puree and cook for 2 minutes. Strain the ground puree and add to this pan. Add fresh cream and mix well. Allow the gravy to come to a boil. Simmer for 1-2 minutes.
Transfer the gravy into a serving dish, place koftas over it and serve hot.