Mango & Passion Fruit Roulade

Impressive and a little intimidating - but actually very simple to make and bursting with sharp, fresh flavours. This size will serve 8 good portions, or much better four with 'seconds'!!  You'll need:

• 4 Egg Whites
  
• 230g Caster sugar
  
• 1.25 tsp Cornflour
  
• 1.25 tsp vanilla extract
  
• 1.25 tsp malt vinegar
  
• 250g Greek Yoghurt
  
• 1 Mango (large, cubed)
  
• 4 Passion Fruit
  
• Icing Sugar (to dust)
  
• Physallis/Chinese Gooseberry (to decorate/Optional!)