Prepare the Beef:

1. Sear the Beef (Optional): In a large skillet, heat olive oil over medium-high heat. Sear the beef chuck roast on all sides until browned, about 4-5 minutes per side. This step adds extra flavor to the beef but can be skipped if you’re in a hurry.
2. Place in Slow Cooker: Transfer the seared beef chuck roast to your slow cooker.

Make the Broth:

3. Mix the Broth Ingredients: In a separate bowl, combine the beef broth, soy sauce, Worcestershire sauce, onion soup mix, garlic powder, thyme, and black pepper. Stir to combine.
4. Pour over the Beef: Pour the broth mixture over the beef chuck roast in the slow cooker, ensuring the meat is mostly submerged.

Slow Cook the Beef:

5. Cook on Low: Cover the slow cooker and cook on low for 7 hours, or until the beef is fork-tender and shreds easily.
6. Shred the Beef: Once the beef is done, remove it from the slow cooker and shred it using two forks. Return the shredded beef to the slow cooker and stir it into the au jus.

Assemble the Sandwiches:

7. Prepare the Rolls: Cut the hoagie rolls in half. Optionally, toast them in the oven at 350°F for 5-7 minutes for added texture.
8. Layer the Beef: Place a generous portion of the shredded beef onto the bottom half of each hoagie roll.
9. Add the Cheese: Top the beef with a slice of provolone cheese (or Swiss cheese).
10. Melt the Cheese: If you prefer melted cheese, place the sandwiches in the oven under the broiler for 2-3 minutes, or until the cheese is melted and bubbly.

Serve and Enjoy:

11. Serve with Au Jus: Ladle some of the au jus from the slow cooker into small bowls for dipping.
12. Enjoy: Serve the sandwiches with the au jus on the side for dipping and enjoy your delicious Slow Cooker French Dip.