Tip the flour into a bowl with 1 tsp salt. Add the suet and butter, and rub into the flour with your fingertips until it resembles fine breadcrumbs. Add 3-4 tbsp cold water and squeeze the crumbs together to form a dough, adding more water if necessary. Press the dough into a flat disc, wrap and chill for 30 mins.
Meanwhile, to make the filling, squeeze the sausagemeat from the skins into a bowl, and combine with the chopped apple and sage.
Dust the work surface with a little flour and split the dough into four even balls. For each ball, roll out to a roughly 20cm square about ½cm thick (don’t worry if the edges are a little uneven). Mould a quarter of the sausage mixture into a log shape and put along the middle of the top half. Spoon 2 heaped tbsp jam along the middle of the bottom half.
Brush the exposed edges of the pastry with a little beaten egg, then fold over the top and bottom ends to meet in the middle and enclose the fillings. Turn the clangers over so the seal is on the bottom, and use a fork to press the ends and seal. Make a few small slashes along the length using a sharp knife to allow steam to escape during baking. Will keep chilled for up to a day. Heat the oven to 200C/180C fan/gas 6 and transfer to a baking tray.
Brush with the rest of the egg and bake for 25-30 mins until golden. (See tip, below, for cooking in the air-fryer.) Cool for at least 15 mins before eating, starting with the savoury end, followed by the jammy end. Will keep chilled for two days.
