01 - Arrange the sliced onion and minced garlic evenly across the bottom of the slow cooker insert.
02 - Rub the chuck roast thoroughly with salt, black pepper, dried thyme, and dried rosemary. Place the seasoned roast directly on top of the onion bed.
03 - Pour the beef broth, soy sauce, and Worcestershire sauce evenly over the beef and onions.
04 - Cover and cook on low setting for 8 hours until the beef is fork-tender and easily shreds.
05 - Transfer the cooked beef to a cutting board. Using two forks, shred the meat into bite-sized pieces. Return the shredded beef to the slow cooker and stir well to absorb the au jus.
06 - Preheat your oven broiler. Split the hoagie rolls horizontally and fill each with a generous portion of shredded beef. Top with a slice of provolone or Swiss cheese if desired.
07 - Arrange the assembled sandwiches on a baking sheet. Broil for 2-3 minutes until the cheese is melted and bubbly, watching closely to prevent burning.
08 - Serve each sandwich accompanied by a small bowl filled with the au jus cooking liquid for dipping.