Pre-heat the oven to 350 fahrenheit, and line two baking sheets with parchment paper.
Roll out the pastry into a thin (1/2 a centimetre) strip, that is apx 4-5 inches wide, and as long as you can get it.
In a bowl, mix the sausage meat with the sage and cranberry sauce. Season with salt a pepper. Place this in a line the long way down the pastry. Carefully fold the pastry over the meat and press to seal with the other pastry, forming pastry sausage! You may find it easier to brush the inside of the dough with water first to help it all stick together.
Carefully slice the pastry sausage into pieces about 2 inches long. Place a one of two slashes through the top to help steam release. Place these onto your prepared baking sheets.
Beat the egg and brush it over the top of the sausage rolls. Place directly in the over for about 20min until the pastry is golden brown. Leave to rest for about 15min before placing on a cooling rack.