Preheat oven to 140C Fan. Line a large baking tray with a sheet of baking paper. Draw a large circle using a plate as a guide (about 30cm).
Make sure your bowl and whisk is totally clean and grease-free. I rub my bowl with a little drop of white wine vinegar - any grease will stop your egg whites whipping up.
Put the egg whites into the bowl of a stand mixer and whisk on high speed for a few minutes until soft peaks form (be careful not to get any yolk in). Then add the sugar 1 tsp at a time, whisking until it forms stiff peaks and is glossy-this can take a good 5-10 minutes.
Mix the vinegar and cornflour together in a cup. Add this to the whisked egg whites along with the vanilla and mix.
Dollop the meringue to fill the circle and use a palette knife or spatula to smooth out the sides. Flatten the middle of the meringue slightly with a spoon, as the filling will be added into this later.
Place into the oven and reduce the temperature to 120C fan. Bake for 60-70 minutes, until hard but still white. Switch off the oven, leave the oven door shut and leave the pavlova inside for an hour or preferably overnight to cool and dry.
To assemble, whip the cream with a hand mixer or with a whisk until it just holds its shape - be careful not to overwhip.
Fold the lemon curd through the cream and spoon onto the meringue. Smooth out with a spoon.
Drizzle over the extra lemon curd. Add fresh fruit of your choice. Best served on the day but will keep in the fridge for 1-2 days.