Place the haggis and sausage meat in a bowl and mix together with a fork until well combined.
Unroll the pastry onto a board and cut in half lengthways. Divide the haggis and pork mixture in two and spread along the length of each pastry strip in a cylinder shape, leaving a 1cm edge. Brush the edges with beaten egg and tightly roll the pastry around the lamb.
Use a sharp knife to cut each roll into approx. 8 to 10 pieces, and place on a baking tray with baking paper.
Prick each sausage roll a couple of times with a fork and then brush with the rest of the beaten egg.
Place in the oven and cook for 30 minutes (turn the tray after 15 minutes so that they cook evenly) until the pastry is puffed and crisp and the meat has cooked through. Remove and place on a wire rack - eat hot or cold.
Notes
This haggis and pork sausage rolls recipe is easily adapted if want to make more.