Steam the chopped mocha in a pressure cooker with salt and turmeric powder.
Strain all the water completely from the mocha.
Run it in a blender to make a paste. Do not make it into a smooth paste. I have blended mocha along with the coconut.
Take the paste of the banana flower in a bowl. To it add salt, ½ tablespoon of ground ginger, 1 teaspoon of Bengali garam masala powder, 1 teaspoon of red chili powder, ½ teaspoon of black pepper powder, ¼ cup of besan, chopped green chilies and mix all the ingredients together.
In a kadai, take oil for frying and heat it. Make balls of the above mixture and gently drop the mocha balls in hot oil.
Fry the mocha koftas on low medium heat and keep them aside.
Now, remove all the oil from the kadai leaving about a tablespoon of oil in the kadai. Then add 1 tablespoon of ghee to the kadai.
As the oil starts smoking, throw in ¼ teaspoon of sahi jeera to the oil.
Then add the grated ginger to the kadai and saute them till the raw smell of ginger is gone.
In a bowl, mix 1 teaspoon of turmeric powder, 1 teaspoon of red chili powder, 1 teaspoon of Kashmiri red chili powder, salt, 1 teaspoon of Bengali garam masala powder, 1 teaspoon of cumin powder along with 2 tablespoon of water.
Pour this mixture into the kadai and continue sauteing the spices till you see oil separating at the sides of the pan.
Meanwhile, in a bowl take the yogurt and whisk it properly. As you see oil separating at the sides of the pan, add the yogurt to the kadai and stir continuously.
Add about ¼ cup of water to the kadai and let it simmer.
Now, add the fried koftas to the kadai and continue simmering till very little water is left in the kadai.
Turn off the flame and keep the kofta gravy aside.