In a large mixing bowl, add bananas and mash.
Add sugar, salt, yoghurt and mix well.
Add baking soda and flour, and knead it well to make a dough. Add more flour if necessary/ if the dough is too wet. It should be the consistency of chapati dough. Cover and rest this dough for 6-8 hours.
Roll it out into small, round shapes.
Deep fry on both sides until golden brown.
The dough can be made at night, and you can roll them out in the morning, ready for a hot breakfast.