1. Preheat your oven to 160 degrees.
2. Put your egg whites into a freestanding mixer and beat until white and fluffy.
3. Add your castor sugar one tablespoon at a time, whisking on high until all the sugar has dissolved and it is stiff and glossy.
4. Fold into the mixture, cornflour and vinegar until just combined.
5. Then pile the mixture onto a lined baking tray or a quiche dish.
6. Bake for 30 to 40 mins until golden just on the edges.
7. Turn oven off and allow to cool inside the oven.
8. Place in the fridge to get nice and cold.
9. Top with whipped cream, passionfruit and your choice of berries.
It's just sinful.