For the mango mousse, peel the mangoes and remove the flesh from the stone. Place the mango flesh into a food processor, blend until smooth and pass through a sieve into a clean bowl.
Add the lime juice, sugar and the softened and drained gelatine leaf. Mix well to incorporate.
Whisk the egg white in a mixing bowl until soft peaks form when the whisk is removed from the bowl.
In a separate bowl, whisk the double cream until soft peaks form when the whisk is removed from the bowl.
Lightly fold the whisked double cream and egg white into the puréed mango with a metal spoon, making sure not to beat all the air out.
Place into a mould or bowl and transfer to the fridge to set for at least two hours.
For the spiced banana fritters, mix together the sugar and chilli powder in a small bowl and scatter over a tray. Roll the bananas in the spice mix.
Roll out the pastry until very thin, cut it into four sheets and carefully wrap the bananas up in the pastry.
Heat the vegetable oil in a deep heavy-based saucepan until a breadcrumb sizzles and browns when dropped in it. (CAUTION: hot oil can be dangerous - do not leave unattended.) Add the bananas to the oil and fry until golden-brown. Remove with a slotted spoon and drain on kitchen paper.
Serve a spiced banana half with a tablespoon of the mango mousse for each person.