01 - Preheat your oven to 400°F and line a baking sheet with parchment paper.
02 - In a large bowl, mix together the ground beef, onion, garlic, parsley, thyme, Worcestershire sauce, salt, pepper, and 1 beaten egg until well combined.
03 - Lay out the puff pastry sheets on a lightly floured surface. Cut each sheet in half lengthwise to make 4 long strips in total.
04 - Divide the beef mixture into 4 equal portions. Shape each portion into a long log and place it down the center of each pastry strip.
05 - Fold the pastry over the filling, pressing the edges to seal. Place the rolls seam-side down and cut each roll into 3 equal pieces (total 12 rolls).
06 - Arrange the rolls on the prepared baking sheet. Mix the remaining egg with milk and brush over the tops for a golden finish.
07 - Use a sharp knife to score small slits on top of each roll for ventilation.
08 - Bake for 20 to 25 minutes, or until the pastry is golden brown and the filling is cooked through.
09 - Let cool slightly before serving.