Preheat your oven to 130 C and place rack in the centre of the oven.
Line a baking sheet with parchment paper and draw a 9 inch circle on the paper. Turn the paper over so the circle is on the reverse side.
Beat the egg whites on medium speed until they hold soft peaks. Start adding the sugar, a spoonful at a time until the meringue holds stiff peaks and is shiny. Make sure the sugar is completely dissolved by rubbing a bit between your fingers. If it is still grainy, continue beating. Fold in the cornstarch, vinegar, and vanilla.
Spread the meringue inside the circle on your parchment paper, making a nest-like shape, with slightly higher edges than the centre. Bake for 60-75 minutes until the outside is dry and a pale cream colour. Turn the oven off, and open the door slightly, let the meringue completely cool in the oven.
Just before serving whip the cream, and the remaining vanilla and sugar. Spread over the top of the completely cooled pavlova.
Spread your fruit on top of the cream in the design of the Union Jack.
Whip some extra cream and use a piping bag to help define the edges of the fruit in your Union Jack design.
Please note: this recipe has been created and uploaded by a member of the Tesco Real Food online community. Tesco does not test customer recipes so cannot accept responsibility for the content, validate the results or answer queries regarding them.