Preheat oven to 150°C (300°F). Place the eggwhite in the bowl of an electric mixer and whisk until stiff peaks form. Gradually add the sugar, whisking well, until the mixture is stiff and glossy.
Add the cornflour and vinegar and whisk until just combined. Shape the mixture into an 18cm round on a baking tray lined with non-stick baking paper. Reduce oven to 120°C (250°F) and bake for 1 hour 20 minutes. Turn the oven off and allow the pavlova to cool completely in the oven. Whisk the cream until soft peaks form. Spread over the pavlova, top with passionfruit and strawberries and serve immediately. Serves 8–10.
* You’ll know when the meringue is stiff and glossy because the mixture will have tripled in volume and stands up when the beaters are lifted.
* The low heat puffs up the meringue while the long cooking time dries it out to give you a lovely crisp shell.
* Store your pavlova, undressed, in an airtight container at room temperature for up to 5 days.