Directions: Preheat oven to moderate 180 degrees C. Brush 30/25/2cm Swiss roll tin with melted margarine. Line base with paper; grease paper. Dust with sifted cornflour, shake off excess.
Place egg whites in small dry mixing bowl. Using electric beaters, beat egg whites until firm peaks form. Add sugar gradually, beating constantly until mixture is thick and glossy and all sugar is dissolved.
Using a metal spoon, fold in cornflour and vinegar. Spread mixture into prepared tray. Bake for 12 to 15 minutes or until well risen and golden brown.
Turn meringue onto a sheet of greaseproof paper that has been lightly dusted with icing sugar. Leave to cool to lukewarm.
To make filling: using electric beaters, beat yoghurt and ricotta cheese until creamy. Covruit pulper and refrigerate 30 minutes before using. Spread filling evenly over cooled meringue and to with sliced strawberries mixed with passionfruit pulp. Using paper as a guide, roll from short side as for a Swiss roll. Cut in thick slices to serve.
Note. Meringue roll can be made a day ahead. Cover loosely with plastic wrap in refrigerator. Chill filling well before using. Meringue needs to be lukewarm for rolling, or it will crack.