Pressure cook the raw bananas in water according to your pressure cooker specifications. Alternatively, these raw banana can be boiled in water on the stove directly.
After the bananas are boiled, remove the skin and mash the bananas and keep aside in a bowl.
Heat oil on medium flame for deep frying.
To the mashed bananas, add onion, chilli powder, salt, green chilli, coriander leaves, gram flour and corn flour and mix thoroughly.
Shape the mixture into small flat fritter and drop slowly into the heated oil for deep frying.
Since the banana is already cooked, fry the fritter until brown on both sides. This should be done until all the mixture is exhausted.
Serve hot with tea as snacks.