clean and chop the banana stem. take them in a pressure cooker along with salt, turmeric and 1/4 cup water. mix well, close and pressure cook for 3-4 whistles.
let the pressure settle on its own. open and drain it completely. let it cool completely.
to make spice powder
meanwhile dry roast Bengal gram until brown and take it in a blender.
heat oil in the same pan and add cinnamon, cloves, green chilli, red chillies, fennel seeds, fried gram, small onions, garlic and fry until brown.
add coconut grated and khus khus. fry for few seconds.
cool and add it to the blender along with roasted Bengal gram.
grind it to coarse powder. keep it aside.
to make the kola
squeeze excess water from the banana stem and take it in the mixing bowl.
add the spice powder, chopped onions, chopped curry leaves, chopped coriander leaves, oil, salt to taste and mix well to thick batter (vada batter consistency)
grease hands and make small balls out of it. freeze all the balls for an hour