Combine cream and yoghurt in a well-chilled bowl and beat together until creamy and thick. Add sweetcorn and spoon into a well-chilled, plastic ice-cream container.
Cover and freeze until it becomes slushy. Turn out onto a chilled bowl and beat well again.
In a separate bowl, whisk the egg whites until stiff. Gradually add in the sugar and continue to whisk until it is very stiff. Fold meringue into sweet corn mixture, return the whole mixture to the ice-cream container. Cover and freeze again until firm.
Transfer the ice-cream to the refrigerator 15-20 minutes before serving to make it easier to scoop.