Preheat oven to 180°C. Heat a large frypan over medium heat. Add the olive oil, silverbeet and nutmeg, season to taste with salt and pepper and cook for 2-3 minutes or until wilted. Remove from the heat and strain through a sieve or colander to drain away any excess moisture.
Place the onion, feta and pine nuts in a large bowl and mix well. Add the wilted silverbeet and mix well. Add the beaten egg and stir to combine.
Cook the potato pieces in boiling salted water, until tender, about 15 minutes. Drain and mash the potato to make a smooth puree. Add milk or nut milk and mix until well combined. Blanch the broad beans in boiling water, then remove the husks from each broad bean, leaving the inner green bean. Fold the broad beans into the mashed potato.
Grease a pie dish (about 24cm x 17cm x 6cm) with the melted margarine. Layer 2 sheets of filo lengthways in the pie dish and brush with melted margarine or spray oil. Lay on another 2 sheets of filo pastry along the width and brush again with the margarine or oil. Repeat this process so you have 4 double layers.
Spoon the silverbeet mixture into the pie dish and spread evenly. Fold the overhanging filo over the filling to enclose. Spread over the mashed potato and broad bean topping. Bake in oven for 50-60 minutes or until golden. Leave to rest out of the oven for 10 mins before serving.
Spinach, cavalo nero or kale can all be used instead of silverbeet.
Sprinkle with parmesan cheese for extra crunch and taste in the topping.
To remove the white stems from the silverbeet, cut a ‘v’ from the green leaf down to the stalk, taking out the centre white stem.