For the pavlova: Preheat oven to low 120C/100C fan-forced. Line a large baking tray (approx. 40cm x 30cm) with baking paper.
Beat egg whites in a clean large bowl with an electric mixer until soft peaks form. Only then add caster sugar, a heaped tablespoon or so at a time, beating until dissolved (to test, rub some mixture between finger if too grainy, keep beating until glossy). Then fold in cornflour and vinegar.
Turn out onto tray; using a palette knife or spatula, spread the mixture across the baking paper (approx. 30cm x 24cm), building up the sides a little and creating a few tips and dips in the meringue as you go. (A wet spoon, spatula or palette knife helps.)
Bake in very slow oven for about 1 ½ hours, or until set and dry (surface should be dry to touch). Turn oven off and prop door ajar with a wooden spoon and cool in oven.
For the curd: Put the strawberries in a small saucepan with the sugar, butter, lemon zest and lemon juice. Stir over low heat until the butter has melted and the sugar dissolved.
Simmer gently for 5 minutes, then remove from the heat.
Lightly beat the egg yolks in a large bowl then, stirring constantly, slowly add the strawberry mixture in a thin stream. The mixture will thicken as you add it.
Return to low heat and cook for 3 minutes, stirring constantly. Do not allow the mixture to boil or the curd will curdle.
Test by running a finger across the back of the spoon to ensure the curd is thick and does not run.
Put into a bowl and cover with plastic wrap to prevent a skin forming.
To assemble: Whip cream with sugar and vanilla.
Spread a small spoon of cream on a flat serving plate.
Place pavlova on top then fill pavlova with curd, cream (ensuring you can still see some of the curd), then berries.
Shave chocolate curls from a block of chocolate using a vegetable peeler.