Line a baking tray with baking paper. Preheat oven 125C.

First clean your mixing bowl with a kitchen towel and vinegar to remove grease. Using an electric beater or stand-up mixer whisk egg whites and salt until stiff peaks form. Slowly add the sugar 1 tbsp at a time mixing thoroughly between each addition. The mixture should be nice and glossy now. The next step is very important or the sugar won't be incorporated into the egg white properly and can 'weep' during cooking. Beat the meringue for 10 minutes. Once you can rub a small amount of meringue between your fingers and feel no sugar grains you are good to go.

Use a large metal spoon to fold through the vinegar, vanilla and corn flour/ tapioca. Dollop the meringue onto the baking paper into 6 x 8cm circles. Don't over work the meringue, just pile it high as it will sink and spread a little as it cooks. Carefully place the pavlovas in the oven in the middle rack and bake for 1 hour then turn off the oven and leave to cool completely inside the oven. I find this is best made the night before if planning a midday Christmas lunch. Or they can be made several days in advance and stored in an airtight container.