Sieve the flour and salt into a large mixing bowl. Cut the butter into one-centimetre pieces cubes and rub it gently through the flour. This doesn’t have to total incorporated as you want some small butter pieces in the mix to help the flaking process.

Mix 150 ml of ice-cold water with the lemon juice and slowly add to the flour and butter mixture. Use your hands to gently bring the ingredients together, but don’t overwork the dough.

Tip the dough out on to a floured worktop and lightly roll out into a small rectangle. Brush off any excess flour and transfer onto a piece of baking paper. Cover and place in the fridge for twenty minutes to rest and chill.

Place back on to the floured surface and roll the dough into a larger rectangle about a centimetre thick. Brush off any flour and divide into three. Fold the bottom third over to the middle and then cover with the top third.

Turn the pastry by a quarter and roll out again and repeat the folding process. Cover and place in the fridge and rest for thirty minutes.

Remove the pastry and repeat the rolling and folding process two more times the return to the fridge to rest.

Fry the mushroom in the butter, season generously and allow to cool. Finely chop the cooked mushrooms and place in a large bowl. Add the egg and bacon pieces.

Preheat the oven to 350 F / 180 / Gas Mark 6. Roll out the pastry on a lightly floured board into a rectangle about half a centimetre thick.

Brush with the egg wash and lay some of the sausage mix along the pastry. Cover the sausage meat with pastry and allow around two centimetres down the side to crimp with your finger or a fork.

Continue until all the sausage mix is used up. Brush the finished sausage rolls with more egg mix and cut into equal sized pieces. Place onto baking trays and bake for thirty-five minutes until golden brown.

Carefully remove from the oven and allow to cool slightly before transferring to a cooling rack. When cool store in an airtight container in the fridge but they are best ate warm just after cooking.