Blend the tomatoes, green chilies and ginger to make a puree. If you prefer a milder version, take the seeds out of the green chili before blending.
Heat the oil in a saucepan on medium-high. Test the heat by adding one cumin seed to the oil; if it cracks right away oil is ready.
Add the asafetida, cumin seeds stir for a minute. Lower the heat to low, add the other spices except garam masala, coriander powder, turmeric, salt sugar, turmeric, and cashew powder. Stir-fry for a minutes.
Add the tomato puree, increase the heat to medium cook until the tomato mixture starts leaving the oil and reduces to about half in quantity. Add cream save about 1 tablespoon for garnishing and cook for another minute.
Add about 1-1/2 cups of water, as it comes to boil reduce the heat to low and let the gravy cook for few minutes.
Note: adjust the thickness of the gravy to your taste by adjusting the water.
Add the prepared koftas and let it simmer for 1-2 minutes.
Turn of the heat and add the garam masala and cover the pot.