01 - Arrange sliced onion and minced garlic evenly across the bottom of the slow cooker insert.
02 - Rub chuck roast thoroughly with salt, pepper, thyme, and rosemary on all sides, then place directly on top of the onion bed.
03 - Pour beef broth, soy sauce, and Worcestershire sauce over the roast and vegetables, ensuring the beef is partially submerged.
04 - Cover with lid and cook on low setting for 8 hours until beef is fork-tender and easily shreds apart.
05 - Transfer cooked beef to a cutting board and shred using two forks, then return meat to the slow cooker and stir well to absorb the au jus.
06 - Split hoagie rolls open, heap shredded beef onto the bottom halves, and top with cheese slices if using.
07 - Place sandwiches on a baking sheet and broil for 2-3 minutes until cheese is bubbly and bread is lightly toasted.
08 - Transfer sandwiches to plates and serve alongside small bowls filled with the reserved cooking liquid for dipping.