Preheat the oven to 140°C.
Whisk egg whites in a glass bowl until soft peaks form.
Add half the sugar and whisk until firm, then fold in the remaining sugar.
Fold in the cornflour and vinegar with a spoon.
Line a tray with parchment and shape the meringue into a nest.
Bake at 140°C for 10 minutes, then reduce heat to 120°C for one hour.
Turn off the oven and leave the meringue inside overnight to cool completely.
Whisk the double cream until soft peaks form.
Spread melted white chocolate in the meringue and fill with whipped cream.
Top with diced mango and passion fruit pulp.
Heat sugar and water in a pan until caramelised.
Cool the caramel for 2 minutes before drizzling over the pavlova.