Method

 

1. Pre- heat oven to 150C/130C (Fan), Gas 2.

 

2. Draw a 20 cm circle on non- stick (silicone) paper and place on a baking sheet.

3. Whisk egg whites until stiff and standing in peaks.
Continue whisking, gradually adding the sugar until very stiff. Beat in vanilla, cornflour and vinegar.

 

4. Spread the mixture over the circle, piling up around the edges to form a case. Use a skewer to make little swirls around the edge.

 

5. Place in oven and immediately turn down oven to 140C/120C (Fan), Gas 1, and leave it to cook for an hour. Then turn oven off and leave it inside until completely cold to dry out. It should be crisp and golden-brown on the outside and soft inside.