Sear the Beef

1. Heat olive oil in a large skillet over medium-high heat.
2. Season the beef chuck roast generously with kosher salt and freshly ground pepper.
3. Sear each side of the roast in the hot skillet for 1-2 minutes until browned.

2. Prepare the Slow Cooker

1. Transfer the seared roast to your slow cooker, along with the pan drippings.
2. Sprinkle onion soup mix over the roast.
3. Add water and beef broth, ensuring the liquid covers the roast halfway.

3. Cook the Beef

1. Cover the slow cooker with the lid.
2. Cook on low for 8-10 hours or high for 4-6 hours, until the beef is tender and easily shreds with a fork.

4. Shred the Beef

1. Remove the roast from the slow cooker and place it on a cutting board.
2. Use two forks to shred the beef into bite-sized pieces. Return the shredded beef to the slow cooker to keep warm in the juices.

5. Assemble the Sandwiches

1. Preheat your oven to broil.
2. Slice the crusty rolls in half and layer each with shredded beef.
3. Top with a slice of Swiss or provolone cheese.
4. Place the sandwiches on a baking sheet and broil for 2-3 minutes, or until the cheese melts and the bread is golden.

6. Serve with Au Jus

1. Ladle the warm broth from the slow cooker into small bowls.
2. Serve the sandwiches immediately with the au jus for dipping.