Lightly roll out each puff pastry sheet with a rolling pin. You just want to extend the puff pastry a bit. Cut each into thirds, lengthwise, you should still be able to see the fold line to guide you.
In a bowl mix together, sausage, onion, potato, sage, salt and red pepper flake. Transfer to a ziplock baggie, cut the tip off and pip the filling along the long edge of the dough. Should be about ½ inch of filling.
Roll dough, jellyroll fashion, seal edges.
Chill for 20 minutes or overnight.
When ready to bake, cut into 1 inch pieces. Place on baking sheet (non-greased), brush with egg wash, and bake for about 20 minutes until pastry is golden brown.
Serve with worteshire sauce.
Recipe by Cooking for Keeps at https://www.cookingforkeeps.com/puff-pastry-sausage-rolls/