- Heat 1 tablespoon oil in a large, non-stick frying pan over high heat. Add the silver beet, salt and pepper and cook, stirring frequently, for 3-4 minutes or until just wilted. Drain well on absorbent paper and set aside. Wipe the frying pan clean and heat 1 tablespoon oil over high heat. add the onion and garlic and cook, stirring frequently, for 2-3 minutes or until golden. Add the mince and harissa and cook, breaking up any lumps with a wooden spoon, for 8-10 minutes or until golden and cooked through. Remove from the heat and stir through the salt and pepper, parsley and sumac. Set aside to cool completely. 
- To make the dough, place the yeast, sugar and water in a bowl and mix to combine. Set aside in a warm place for 5 minutes or until bubbles appear on the surface. Place the flour and salt in a bowl and make a well in the centre. Add the yeast mixture and mix together with well-floured hands to form a dough. Turn out onto a lightly floured surface and knead for 3-4 minutes or until smooth and elastic. Place in a lightly greased, large bowl under a clean, damp cloth and set aside in a warm place for 15-20 minutes or until doubled in size. 
- Divide the dough into 4 pieces and roll out on a lightly floured surface to 25 x 35cm rectangles. Place the silver beet, mince mixture, feta and havarti (or mozzarella) cheese onto one side of the rectangles, leaving a 2cm border. Brush to remove any excess flour. Fold the dough over to enclose the filling and press the edges to seal. 
- Heat a large, non-stick frying pan over medium heat. Brush the gozleme with oil and cook, in batches, for 3-4 minutes each side or until golden and cooked through. Serve with yoghurt, lemon wedges and a sprinkle of sumac.