This clanger has a rich, spicy tomato-and-herb-based filling with sweet potato chunks, piquanté peppers, chickpeas, feta cheese, and pine nuts.
Make the filling. Put the sweet potato dice into a medium pan, cover with cold water, then bring to the boil over a high heat. Reduce the heat and simmer for 5 minutes, then drain and set aside.
Heat the olive oil in a deep frying pan over a low heat. Stir in the onions and cook gently, stirring frequently, for about 10 minutes, until very soft and transparent. Turn up the heat and fry, stirring, until a rich golden brown – don’t let them burn.
Stir in the garlic, chilli flakes, sumac (if using), cumin, coriander and paprika followed by the pomegranate molasses, honey and the chopped tomatoes. Stir well, bring to the boil and leave to simmer, stirring frequently, for 20 minutes, until well combined.
If the mixture is too loose, turn up the heat and keep cooking (and stirring) until very thick, almost like a paste. Remove the pan from the heat and leave until completely cold. Heat the oven to 220°C/200°C fan/425°F/Gas 7.
Make the pastry. Sift the flour, salt and sugar into a mixing bowl, then stir in the suet. Dip the piece of frozen butter in the flour, then grate it into the bowl, using the coarse side of a grater. Make a well in the centre.
Add the vinegar to the icy water and gradually stir into the flour mixture to make a soft but not sticky dough. Turn out onto a lightly floured worktop and knead until smooth. If the dough feels sticky, wrap it in cling film and chill until firm enough to roll.
Dust the worktop and rolling pin with flour. Divide the dough into 4 equal portions, then roll out 1 portion to a 22 x 26cm rectangle, with one long side facing you.
Combine the filling. Stir the sweet potatoes into the cooled tomato mixture, followed by the chickpeas, peppers, cheese, pine nuts and herbs. Season to taste.
Brush a 1cm border of beaten egg all around the edges of the dough rectangle, then spoon a quarter of the filling along the length of the dough to make a strip 6cm wide and 24cm long.
Flip the short edges of the rectangle over the filling, then fold over the long edge furthest away from you and fold the bottom half up to meet it to enclose the filling. Press the seams together to seal.
Gently flip the clanger over onto the lined baking sheet so the seam is underneath. Brush with beaten egg, then cut 4 small slashes across the top. Repeat with the remaining portions of dough and filling.
Bake for about 25 minutes, until the pastry is golden brown and crisp. Serve hot from the oven.