Line 2 baking sheets with baking parchment. Preheat the oven to 210ºC/gas mark 7. Draw 3 circles on baking parchment, the first 10cm in diameter, another 18cm and the last 25cm (use plates, saucers or cans as a guide).
Stir together the cornflour and vinegar in a small bowl until well blended. In a large, clean bowl, whisk the egg whites and salt with a handheld whisk, or in an electric mixer, until they hold their shape in soft peaks. Add the sugar 1 tbsp at a time, alternating with a little of the cornflour. The meringue should be thick, shiny and marshmallowy.
Using a spatula, spread the mixture into the 3 drawn circles. Keep the discs reasonably flat. Put them in the oven and immediately reduce the temperature to very, very low (mine was at 80ºC/gas mark ¼). Bake for 1¾ - 2 hours. They should be crispy and dry on the outside and may be a bit cracked, which is fine. Give them a bit longer in the oven if necessary, but they may start to colour a little; try to keep them as white as possible. Turn the oven off, leave the door slightly ajar and allow them to cool completely in the oven.
Whip the cream until soft peaks form, then fold in the vanilla and sugar to taste. Half fold in the lemon curd. Cut open the passion fruit and scoop out the seeds. Peel and stone the mango and chop. Peel the pineapple and chop into bite-sized pieces. Deseed the pomegranate.
Place the largest meringue on a serving plate. Spread with some cream, then a layer of fruit, reserving a few pomegranate seeds. Add more cream, then place on the 18cm meringue. Repeat with the remaining cream and fruits and top with the smallest meringue. Sprinkle with the reserved pomegranate, dust liberally with icing sugar and a little edible glitter, if you wish.