Preheat oven to 140 degrees C/ Gas mark 1. Cover a baking tray with a sheet of silicone paper.
In a large, very clean bowl, whip egg whites until fluffy.
Add sugar, one tablespoon at a time.
When thick and glossy, spoon the meringue mixture on to the prepared baking sheet, forming a circle about 8 inches (20 cm) wide.
Bake for one to one and a half hours. Set aside to cool.
Place condenesed milk into microwave bowl, heat on full power stirring every minute until thick and drops off the spoon like runny toffee. Leave to cool.
Whip the cream and stir in seeds from vanilla pod.
When pavlova has cooled, pour over toffee, top with vanilla-cream and decorate with grated chocolate.
You can also place the tin of condensed milk (unopened) into a saucepan of water. Boil gently for 3 hours taking care not to let pan boil dry. This gives a really smooth toffee and is the way I prefer to do it.