Cut two pieces of greaseproof paper large enough to cover the base of your baking sheets.
Draw circles of 8cm onto the greaseproof paper, leaving a gap of a minimum of 2 cm in between, place on the baking sheet drawn side down.
Heat your oven to 150°C/130°C Fan/300°F/Gas mark 2, making sure the oven racks are set one in the centre and one below.
Fit your stand mixer with the whisk attachment.
Ensure your mixing bowl is absolutely clean, any grease on the surface will prevent your eggs from whisking properly.
Add your egg whites and white wine vinegar to your bowl and whisk slowly until frothy.
Turn up the speed to medium-high and whisk until the egg whites form soft frothy peaks
Turn your mixer down to a low-medium speed and add dessert spoonful's of sugar steadily, one after another, until all of your sugar has been added.
Turn your mixer back up to a medium-high speed and whisk for about 2 minutes, or until the meringue forms stiff peaks. If you can turn the bowl upside down and nothing falls out it is done!
Sprinkle over your cornflour and gently fold in with your large metal spoon, just a few folds should be enough, don't over mix.
Pop your Nutella in a microwave for 10 seconds to soften.
Taking a teaspoon dribble over your Nutella across the top of your meringue, don't worry if it falls in globules.
Take a large star piping nozzle and add it to a piping bag, then place it in a pint glass and fold over half of the piping bag down the outside of the glass, so that you can easily fill half of the piping bag.
Using a desert spoon, spoon the meringue into the piping bag, pulling it through the Nutella topping to create a swirl effect.
Starting at the centre of one of your greaseproof paper circles, pipe a swirl of meringue,. When you return to your starting point raise the nozzle so that you swirl across the base layer to create a nest effect.
Bake for 25 minutes, then turn the oven off completely and leave in the oven to cool - minimum 1 hour.