Meringue towers with prickly pear cream

Preheat the oven to 140 ºC. Lightly spray two baking sheets with non-stick spray and dust with cornflour. Make impressions in the cornflour using a glass about 7 cm in diameter: Beat the egg whites and salt together until soft peaks are formed. Add the castor sugar by the spoonful, beating continuously. Beat until stiff and the mixture holds its shape. Add the vinegar and cornflour. Spoon the mixture into a piping bag and pipe flat circles on the depressions made on the baking tray. Bake for about 35-40 minutes or until the meringues are dry and crisp. Switch off the oven and leave the meringue circles to cool in the oven. Purée the ripe prickly pears in a food processor. Rub the purée through a sieve to remove the seeds. Whip the cream until stiff and fold in the castor sugar and vanilla essence. Just before serving fold the prickly pear purée into the cream and chill. Spoon a little of the cream on a plate. Place a meringue circle on each plate and spoon a little of the cream mixture over the meringue. Repeat until there are three meringue layers. Decorate with puréed mango, fresh fruit and prickly pear slices.