Lay a sheet of silicon or baking parchment on a baking tray.
Preheat oven to 325°F.
Whisk the egg whites in a clean, dry bowl until they are stiff.
Whisk in the sugar a spoonful at a time. Blend the vinegar with the cornflour and whisk it, with the last spoon of sugar, into the egg whites.
Spread the meringue out to roughly an 8” circle on the baking tray and build up the sides so that they are higher then the centre, this is for the filling.
Put the baking tray in the centre of the oven, turn the heat down to 300F and bake the meringue for 1 hour. Turn the oven off but leave the pavlova in the oven to become quite cold (otherwise it might split open as it cools).
Remove the pavlova from the baking tray and place on a serving dish.
Place the condensed milk, cream and lemon juice in a bowl, beat until blended (taste after you just mixed it, you might want to add more condensed milk or lemon, to suit your taste) and the mixture is thick and creamy, then pile into the centre of the pavlova.
Place in the fridge and leave to stand for at least 1 hour before serving.
Peel and slice the kiwi fruit and arrange attractively around the edge of the lemon pavlova just before serving.