Heat the oven to 180C/160C fan/gas 4. Sprinkle the chopped bacon over an oven tray and cook in the oven for 5 mins until crisp. Leave to cool.

Unroll the pastry sheet on its baking parchment, then cut in half lengthways to create two long rectangles. Twist each sausage in the middle, then arrange half of them end-to-end down the middle of one of the pastry rectangles. Sprinkle over half the crisp bacon pieces. Brush the long edge of the pastry closest to you with a little of the beaten egg. Repeat with the remaining sausages, pastry rectangle, bacon and a little more beaten egg.

Fold the unglazed edge over the sausage filling on each pastry rectangle, tucking it against the sausages. Fold the glazed edge over that so it overlaps, pressing it gently along the length to seal. Turn the sausage rolls over, tucking the sealed edge underneath, then gently squeeze the pastry around the sausage filling to enclose completely. Press in gently at each end of the sausages, as well as where you twisted the sausages in the middle, then use a sharp knife cut each roll where the dips are (this will ensure each roll contains a whole piece of sausage). Carefully lift the sausage rolls, still on the parchment, onto a baking tray. The rolls can now be frozen on the tray and, once solid, transferred to a freezerproof container and frozen for up to three months.

Brush the top of each roll with the remaining beaten egg and sprinkle over some sea salt. Bake for 25-30 mins (or 40 mins from frozen) until golden brown. Leave to cool for at least 10 mins before eating.