Preheat the oven 135°C / 275°F / Gas Mark 1 and prepare a large flat tray by lining with nonstick baking paper.
Beat egg whites until foamy. Add the cream of tartar and beat until soft peaks form. Continue beating while gradually adding the sugar one tablespoon at a time. Continue beating until the meringue is thick and glossy and the sugar has dissolved. Rub a little meringue between fingers. If still "gritty" with sugar, continue to whisk until sugar dissolves.
Remove the bowl from the stand mixer and gently fold in the sifted cornstarch, followed by the vanilla and the vinegar.
Pile the mixture onto the baking paper lined flat tray. It should be about a 20 - 25cm / 8 - 10" circle. Hollow out the centre a little.
Bake for 1 ¼ hours. If your oven runs hot and the pavlova is colouring simply lower the temperature by 5 or 10 degrees.
Cool in the oven with the door ajar.
Once cool store in an airtight container unless using straight away.
In a medium saucepan place passionfruit pulp, lemon juice, butter and sugar. Cook over a medium heat until the butter has melted and the sugar has dissolved.
In a bowl place eggs and additional egg yolks and whisk eggs until combined.
Whisk the eggs and slowly pour in the passionfruit mixture. It is important to keep whisking while you do this. Strain the passionfruit curd mixture through a sieve back into the saucepan to remove any “eggy bits”.
Add the passionfruit seeds and continue to cook over a low/medium heat until the mixture has thickened and coats the back of a spoon. At low heat this can take as long as 10 minutes. At medium heat it can take as little as 5 minutes.
Be careful not to overheat and overcook the mixture – you will then have passionfruit flavoured scrambled eggs. I like to not risk further cooking of the curd by pouring the cooked mixture into a glass jug until cooled.
Once mixture has cooled place in a sterilised jar and store in the fridge. Passionfruit curd will last for a couple of weeks in the fridge.
Using a hand whisk or electric whisk, beat the cream, powdered sugar and vanilla in a stainless steel or glass or china bowl (not plastic doesn't seem to whip as well).
It is whipped properly when it is still soft and billowy but holds its shape when the whisk is withdrawn.
Once the cream is whipped, cover and store in the fridge.
Remove the baking paper from the pavlova and place on a serving tray. (I recently saw Nigella Lawson prepare a pavlova and she simply turned it upside down on a serving tray, removed the baking paper and decorated the pavlova. Once decorated no one could tell it was upside down.)
Spread the Chantilly cream over the pavlova, drizzle with as much of the curd as you like, decorate with slice kiwi fruit and sprinkle with toasted coconut.
This recipe can be halved or increased quite easily just keep in mind that the cooking time will vary. I often make this into a 6 egg white pavlova. Make sure your whisking bowl is clean and greasefree. If in doubt rub with paper towel dipped in white vinegar or lemon juice before use. Have everything ready on the bench because once you start mixing, your pavlova you can’t be interrupted. Use eggs at room temperature to ensure the best whip. The egg whites must not contain even a trace of yolk. To be sure separate each egg individually. I like to use cream of tartar to stablise the whites. I have read that a ½ teaspoon of white vinegar or lemon juice or even a pinch of salt can be substituted but I can’t verify this. If you can’t get superfine sugar, whiz regular sugar in the food processor. Do not open the door during the cooking then when baled. allow to cool slowly in the oven with the door ajar.