Using a sharp knife, cut down either side of the silverbeet stalks and discard stalks. Wash the leaves and pat dry with a tea towel. Roll leaves together and shred with a sharp knife.
Place the bacon and nions in a large saucepan over medium heat. Cook, stirring often, for 4-5 minutes or until golden brown. Add silverbeet and stir to combine. Remove from heat and let stand until the silverbeet wilts. Preheat oven to 180c.
Whilst mixture is standing, make the pastry mix according to the instructions on the packet and line a large baking tray with the pastry.
Spread the silverbeet mixture over pastry base. Whisk the eggs and cream together in a jug and pour over the silverbeet mixture. Cook for 40 minutes and remove from the oven. Sprinkle the cheese over the top and return to the oven for another 20 minutes or until set in the centre. Serve hot or at room temperature.
Frozen shortcrust pastry can be used instead of making the pastry.
Leave the bacon out for a vegetarian alternative.
Add some chopped chillies and crushed garlic for an added "WOW" factor.