Preheat oven to 160°C and line a tray with parchment marked with 30cm and 15cm circles.
Whisk egg whites to soft peaks, then gradually add sugar until stiff and glossy.
Stir in the smooth mixture of vinegar and cornflour.
Spoon meringue onto the parchment ring and create a shallow trench for the filling.
Reduce oven to 140°C and bake for 60 to 75 minutes until the exterior is hard.
Turn off the oven and leave the meringue inside to cool and dry completely.
Whip cream, vanilla, and icing sugar together until stiff peaks form.
Fill the meringue trench with cream and top with berries and pomegranate seeds.
Decorate with mint leaves, dust with icing sugar, and cut into wedges to serve.