Make Kofta: Pressure cook jackfruit and potato until tender, about 3~4 whistles. Let the pressure come down, then drain the excess water from the veggies and mash them well with a potato masher or simple blend it in the blender.
Heat 2tsp oil in a nonstick pan, add the finely chopped onion, green chili and cook till the onion turns lightly browned around the edges.
Next add the ginger+garlic paste, red chili powder and cook for 1 minutes.
Add the mashed potato~jackfruit mixture and season with salt and garam masala.
Cook for 5~7 minutes until the mixture becomes dry and starts to pull away from the pan. Taste and adjust the seasonings. Turn off the heat and let the mixture cool.
Once cool, divide the mixture into equal size balls.
Heat oil in a pan and deep fry the koftas on medium heat until nicely browned all over. Remove onto a paper towel lined plate and set aside.
Make the Gravy: Heat 2tsp oil in a pan, add the onion and cook till lightly browned around the edges. Take off the heat and let cool, then grind to a paste.
Heat 2tbsp oil in a pan. Add the bay leaf, cardamom, grated ginger and cook till fragrant, about 30seconds to a minute.
Add the onion paste and cook for 2~3 minutes.
Next add the tomato puree, tomato paste and cashew (or almond) butter. Cook till the oil starts to separate around the edges, about 4~5 minutes.
Add the red chili powder, coriander powder, cumin powder and turmeric cook for a minute.
Next add enough water to get to desired consistency and let the gravy come to a boil. Season with salt and sugar (if using). Finally add the cream and cook for 1~2 minutes.
To Serve: Place the gravy in a serving bowl and add the koftas to it. Serve with roti or rice. I served this with some Bengali Vegetable Pulao.