Add about 1/3 of the whipped cream to the banana mixture, stirring well to combine. Fold the banana mixture into the rest of the whipped cream and whip it a few times to help incorporate, if necessary.
Refrigerate in little glasses about 30 minutes, or until needed. Before serving, use a vegetable peeler to slowly shave chocolate curls on top of the mousse. The key is to go slowly. Also, milk chocolate is easier to curl than the more brittle dark chocolate.