To make dough
Put flour and salt in bowl of food processor. Whizz and drizzle in the oiland then the water. Continue to process the dough for about a minute until itforms a ball. Remove to a floured surface and knead for 2-3 minutes until it is supple and smooth. Place in a bowl,cover with a cloth and refrigerate for 2 hours to relax the gluten.
Preheat oven to 200C. Lightly oil a 28cm pizza tray.
To make the filling
Finely shred and chop the leaves and stalks of the silverbeet or chard. Placein a colander and toss with the tablespoon of salt. Leave for 20 minutes,then quickly rinse and squeeze dry in a clean cloth.
Transfer silverbeet to a bowl with the chopped potato,diced onion,parsleyand cheese. Season with pepper. Whisk the egg with 1 tbsp of extra virgin olive oil and mix through filling. Taste for salt.
To assemble
Roll two-thirds of the dough on a floured surface into a circle that will easily cover the base of the pizza tray.
Spoon on the filling,leaving a 2cm border of dough.
Stretch back the edge of the dough over the filling,pleating it as you go (see photo at right).
Dampen with water. Roll remaining dough a little smaller and drape it over the filling. Press to seal with the pleated edge. Pierce here and there with a fork,then drizzle the top of the torte with the remaining tablespoon of oil. Scatter with a few grains of sea salt.
Bake for 20 minutes or until golden. Leave to settle for 10 minutes before cutting.