Melt the chocolate (see
Mix the cornflour with the vinegar and vanilla essence, then fold into the meringue. Add the melted chocolate and fold together briefly for a marbled effect. Spoon the meringue into 6 mounds on a large baking sheet lined with nonstick baking paper, then swirl into circles with the back of the spoon, making a slight indentation in the centre.
Bake in a preheated oven, 110°C (225°F), Gas Mark ½, for 1¼–1½ hours or until the pavlovas may be easily lifted off the paper. Leave to cool.
Whip the cream, when ready to serve, until it forms soft swirls. Grate the rind of 1 orange and fold into the cream. Slice off the top and bottom of each orange, then cut away the rest of the peel. Remove the segments, add any juice to the cream, then spoon this over the pavlovas. Arrange the segments and grate a little dark chocolate on top.