Steam the bananas without peeling. Take bananas out of the steamer, peel and mash while still hot. Add salt, green chilli paste, sugar, lemon juice, coriander leaves and mix well till smooth.
Set aside. Take the bajra flour in a bowl. Add refined flour and salt and mix.
Add one tablespoon of oil and sufficient water and knead into a soft dough. Divide into eight even sized pedas.
Sprinkle some refined flour the worktop, place a peda over and gently spread it out with your fingers taking care that the outer edges are thinner than the centre.
Place a portion of the stuffing in the centre and gather the edges and roll into a peda again. Press the peda lightly over roasted sesame seeds on one side.
Roll in refined flour and place it on the floured worktop. Gently spread the peda once again to as thin a roti as you can.
You need not use a rolling pin to do this. Heat a tawa and place the roti over it.
When one side is lightly roasted, turn over and roast the other side.
Drizzle some oil all around and continue to roast till both sides are light golden. (why using word roasted here to cook roti, normally you write cook till brown specks occur and turn; drizzle oil and shallow fry etc;). Serve hot.