Remove the skin and fibres of the banana and cut it into small pieces. Peel the skin and remove the seeds of the papaya. Take out the soft flesh of the papaya with a spoon. Heat the banana and papaya pieces together with some water. When cooked, smash the pieces and sieve the pulp from it.
Boil the pulp in an aluminium or steel vessel. Stir continuously with a wooden ladle. When it boils add the sugar slowly into it. Boil it well by stirring continuously. To test whether the jam is done, pour some jam on a dry plate. Allow it to cool and tilt the plate. If it is done, the jam will fall in flakes. Then add the citric acid to it (if needed add the essence) and remove from fire and pour into a dry bottle. When the jam cools, close the mouth of the bottle.