Whisk the egg whites in a large clean bowl until stiff. Gradually whisk in the sugar, a teaspoonful at time, until it has all been added. Whisk for a few minutes more until the meringue mixture is thick and glossy.
Combine the vinegar and cornflour then whisk into the meringue mixture. Spoon into a 33 x 23 cm (13 x 9 inch) Swiss roll tin lined with nonstick baking paper that stands a little above the top of the tin sides, then spread the surface level. Bake in a preheated oven, 190°C (375°F), Gas Mark 5, for 10 minutes until biscuit coloured and well risen, then reduce the heat to 160°C (325°F), Gas Mark 3, for 5 minutes until just firm to the touch and the top is slightly cracked.
Meanwhile, cover a clean tea towel with nonstick baking paper and sprinkle with a little caster sugar. Turn out the meringue on to the paper. Remove the tin. Leave to cool for 1–2 hours. Carefully peel off the lining paper.
Fold the lime rind into the whipped cream. Spread over the meringue then sprinkle with the blueberries and passion fruit seeds. Starting with a short side and using the paper to help, roll up the meringue to form a log. Serve the same day.