Preheat the oven to 400°F (200°C).
Roll out the puff pastry on a lightly floured surface.
Cut the pastry into rectangles, approximately 3x5 inches.
Spread a thin layer of Dijon mustard on each rectangle.
Place a sausage at one end of each pastry rectangle.
Roll the pastry around the sausage, sealing the edge with the beaten egg.
Place the wrapped sausages on a baking sheet lined with parchment paper.
Brush the tops with the remaining egg wash and sprinkle with spices, if using.
Bake for 15-20 minutes or until golden brown and puffed.
Allow to cool for a few minutes before serving.