01 - Arrange sliced onion and minced garlic evenly in the bottom of the slow cooker insert.
02 - Rub chuck roast thoroughly with salt, pepper, thyme, and rosemary. Place seasoned roast directly on top of the onion bed.
03 - Pour beef broth, soy sauce, and Worcestershire sauce over the roast and onions.
04 - Cover and cook on low setting for 8 hours until beef is fork-tender and easily shreds.
05 - Transfer cooked beef to a cutting board. Using two forks, shred meat into bite-sized pieces. Return shredded beef to the slow cooker and stir well to absorb the au jus.
06 - Set oven to broil. Split hoagie rolls open and fill each with generous portions of shredded beef. Top with cheese slice if desired.
07 - Arrange assembled sandwiches on a baking sheet. Broil for 2-3 minutes until cheese is melted and bubbly. Watch closely to prevent burning.
08 - Ladle hot au jus from the slow cooker into individual dipping bowls. Serve sandwiches immediately alongside the dipping sauce.