Preheat the oven to 200°C (400°F) and line a baking tray with parchment paper.

Combine ingredients in a large mixing bowl: pork mince, French onion soup mix, ketchup, Worcestershire sauce, and Dijon mustard; season with pepper.

Halve each puff pastry sheet lengthwise, creating strips. Place a log of the sausage mixture down the center of each strip.

Whisk together the egg and milk; brush one edge of the pastry with this mixture.

Roll the pastry around the sausage log, sealing the edges securely.

Brush the tops of the rolls with the remaining egg mixture.

Arrange the prepared rolls on the baking tray, leaving some space between them.

Bake for 20-25 minutes until golden brown and filling is cooked through.

Cool slightly before serving.