Place the pork sausage meat and the grated mature cheddar cheese in a mixing bowl and mix this until well combined.
Roll our half of the pastry and cut 4 rectangles of 6 inches by 16 inches, or 15cm by 40cm.
Arrange the filling across the center of each piece of pastry in a long sausage formation.
Lift the edge closest to you up and over the filling. Roll it over to totally enclose the filling. Complete the other 3 rolls and transfer them to a lightly greased baking sheet.
Using a sharp knife, cut through the tops of the sausage rolls at ¾ inch intervals.
Brush the sausage rolls with the egg wash consisting of an egg yolk whisked together with a tablespoon of water.
Grind fresh cracked black pepper liberally over the pastries and bake the pastries in a preheated oven at 200c or 400f for 30 minutes until golden.
Remove the sausage rolls from the oven, cut them apart, transfer to platters and serve immediately.
Recipe by Whats4Chow at https://whats4chow.com/2015/05/05/snack-platter-catering-part-10-super-cheesy-cocktail-sausage-rolls/