Season the roast

• Season the chuck roast evenly on all sides with the garlic powder, onion powder, black pepper and buttery garlic and herb seasoning.

Sear the roast

• Melt the butter in a large skillet over medium-high heat.
• Sear the chuck roast on all sides until nicely browned.
• Transfer the roast to the slow cooker.

Add the au jus base

• Sprinkle the au jus gravy mix and beefy onion soup mix over the roast.
• Add the Worcestershire sauce and chicken broth.

Caramelize the onions

• Melt the butter in the same skillet.
• Add the sliced onion and cook over medium heat, stirring occasionally, until softened and lightly caramelized.

Slow cook

• Spoon the onions directly over the roast.
• Cover and cook on low until the beef is fall-apart tender.

Shred the beef

• Remove most of the cooking liquid from the slow cooker.
• Shred the roast with two forks.
• Return the beef to the slow cooker and toss it with some of the onions and juices.

Assemble the sandwiches

• Pile the shredded beef and onions onto the buns and top with provolone cheese.
• For extra melty cheese, place the assembled sandwiches under the broiler for a minute or two.

Serve with au jus

• Ladle some of the cooking liquid from the slow cooker into small bowls and serve alongside the sandwiches for dipping.