Lay a sheet of silicone paper on the cold plain shelf and mark an 200mm circle on it. Whisk the egg whites until they are stiff then whisk in the sugar a tspful at a time until all added.

Blend the vinegar with the cornflour and whisk in.

Spread the mixture out to cover the circle on the silicone paper building up the sides so they are higher than the centre.

Slide the baking sheet onto the grid shelf on the floor of the oven for about 3 to 4 minutes until lightly coloured.

Then transfer to the simmering oven for 1 to 1 1/2 hours until firm but still gooey in the centre.

If the Pavlova is not cooked it may be necessary to turn it over and leave upside down in the simmering oven to dry out the underneath.

Allow to cool peel away paper and place on a serving plate.