Preheat the oven to 220°C (425°F) Gas mark 7. Lightly grease a Swiss roll tin (33cm x 23cm) and line with non-stick baking parchment. Place the egg whites in a spotlessly clean bowl and whisk with a hand-held electric mixer on a high speed until very stiff.

Now add the sugar a tablespoon at a time and, keeping the mixed on high heat and whisking well after each addition. Whisk until very stiff and glossy. Reduce the speed to low and add the vanilla, vinegar and cornflour and whisk until well combined. Spoon into the prepared tin, using a spatula to spread the meringue out evenly.

Place the meringue in the oven and immediately lower the temperature to 180°C (350°F) Gas mark 4 and bake for 20-25 minutes until crisp and firm to the touch. It should be a nice pale beige colour. Remove from the oven and turn top side down on to a large sheet of non-stick baking parchment. Carefully peel the paper off the base of the cooled meringue and leave to cool completely.

Put the cream in a bowl and whip until soft peaks form. Spread two-thirds evenly over the meringue. Cut the stalks off the strawberries and then dice and scatter over the cream mixture.