Roll out the pastry to a 35 x 30cm rectangle on a surface lightly dusted with flour. Trim the edges neatly, then cut in half lengthways to form two long strips. Spread with a thin layer of the apple sauce, pickle or chutney, leaving a border along the edges.
Tip the sausagemeat into a large bowl, add 3 tbsp cold water and squash together. Divide the mixture in two and mould each half into a cylindrical shape. Put each portion of meat into the middle of a pastry strip, leaving a border at either side. Brush the pastry border and the top of the sausage mix with the beaten egg. Fold one edge of the pastry over the meat and roll to encase, then use a fork to press the pastry edges together. Cut the sausage rolls into 5cm lengths and arrange on a lined baking tray. Chill for 20 mins. Can be made a day ahead or frozen for up to one month; to bake from frozen, add an extra 10 mins to the cooking time.
Heat oven to 200C/180C fan/gas 6. Brush the sausage rolls with the rest of the beaten egg and sprinkle with the sesame seeds or nigella seeds (if using). Bake for 30-35 mins until the pastry is deep golden. Transfer the sausage rolls to a wire rack and leave to cool for 10 mins.
View the recipe instructions at BBC Good Food
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