01 - Arrange sliced onions and minced garlic evenly across the bottom of the slow cooker insert.
02 - Rub the chuck roast thoroughly with salt, pepper, thyme, and 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 roast and aromatics.
04 - Cover and cook on low setting for 8 hours until the beef pulls apart easily with minimal resistance.
05 - Transfer the cooked beef to a cutting board and shred using two forks. Return the shredded meat to the slow cooker and mix thoroughly with the accumulated juices.
06 - Preheat the oven broiler. Slice the hoagie rolls lengthwise and fill each generously with the shredded beef. Top with cheese slices if using.
07 - Arrange assembled sandwiches on a baking sheet and broil for 2-3 minutes until the cheese is fully melted and beginning to bubble.
08 - Serve sandwiches immediately alongside small bowls filled with the au jus from the slow cooker for dipping.