In a bowl mix the cornflour, sugar and vanilla pod and put to one side.
Put the egg whites and salt in a separate clean bowl and mix, add the vinegar and gradually add the sugar/corn flour/vanilla mix until the meringue looks glossy.
Line a baking tray with greaseproof paper. (TOP TIP add a dot of meringue mix to four corners of the baking tray to fix the greaseproof and stop it moving while you are piping the meringue).
Pipe the mixture into nests or rosettes.
Place tray into the preheated oven for 1hr 20mins.
While the meringues are in the oven prepare the filling - whisk the double cream, castor sugar and vanilla pod.
Add a spoonful of the cream mixture to each cooled meringue and top with red berries.
