In a mixing bowl, combine the sausage meat with the apple and red onion marmalade and parsley, season and mix well.
Unroll the pastry and place on a lightly greased baking tray. Place the sausage mixture down the middle of the long length of the pastry. With a sharp knife, cut slits 3cm/1in apart, 1cm/½in away from the sausage mixture to the edge of the pastry, slanting away from you. Brush with beaten egg.
Starting at the end nearest to you, fold the pastry alternately over each other, to give a 'plait' effect. Brush the top with beaten egg.
Bake in the centre of the oven for 40 minutes, reducing the temperature to 150C/300F/Gas 2 after 20 minutes. Allow to stand for 5 minutes before serving.