Place the chuck roast into a slow cooker. In a bowl, whisk together the beef broth, onion soup mix, Worcestershire sauce, and soy sauce. Pour over the roast.

Cover and cook on LOW for 8 hours or HIGH for 4-5 hours, until the beef is very tender and shreds easily.

Remove the beef from the slow cooker and shred it with two forks. Strain the remaining liquid from the slow cooker through a fine-mesh sieve into a saucepan to use as the au jus dipping sauce. Keep warm.

Preheat your oven to 400°F (200°C). Line a large baking sheet with parchment paper.

On a lightly floured surface, gently roll out one sheet of puff pastry to smooth the creases. Transfer to the prepared baking sheet.

Layer the provolone cheese over the pastry, leaving a 1/2-inch border around the edges. Top the cheese with an even layer of the shredded beef.

Roll out the second sheet of puff pastry and place it over the beef. Press the edges of the top and bottom pastry sheets together firmly to seal.

Brush the top of the pastry evenly with the egg wash. Use a sharp knife to gently score the top into 12 squares (do not cut all the way through).

Bake for 20-25 minutes, or until the pastry is puffed and golden brown.

Let cool for 5 minutes before slicing completely through the scored lines. Garnish with fresh herbs and serve warm with the reserved au jus for dipping.