Measure water into a medium size mixing bowl. Sprinkle contents of the pack over the water and beat until well blended. Cover with clingfilm. Leave in the fridge for 5 minutes.
In a smaller mixing bowl whip the cream until soft peak stage.
Remove the Mousse mixture from the fridge. Using the same beaters, whip the mousse mixture again until smooth. Gently fold the whipped cream into the mousse using a spatula or metal spoon. Stir until evenly blended.
Layer the mousse with sliced bananas and a light sprinkling of nuts. End with the mousse layer and top with nuts. Cover and refrigerate until ready to serve.
Bananas are a very good source of potassium, which is a vital mineral for muscle and nerve function. Best to eat banana when fully ripe, like the ones in the photograph.