Whisk the egg whites in an electric mixer until soft peaks form.
Slowly add the sugar and vinegar and whisk until stiff peaks form.
Place in a greased springform pan and bake at 300 for about 45 minutes or until merengue is browned.
Meanwhile, heat blueberries and sugar in a saucepan and cook for about 10 minutes, until they become thick and syrup like, yet blueberries remain whole. The sauce should coat the back of a spoon.
Allow to cool, then pour over the pavlova merengue crust.
A dollop of whipped cream would be a lovely addition!