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. Place seasoned roast directly on top of the onion layer.
03 - Pour beef broth, soy sauce, and Worcestershire sauce evenly over the beef and vegetables.
04 - Cover with lid and cook on low setting for 8 hours until beef is fork-tender and easily pulls apart.
05 - Transfer cooked beef to cutting board. Using two forks, shred meat into strands. Return shredded beef to crockpot and stir thoroughly to absorb au jus.
06 - Set oven to broil. Slice hoagie rolls lengthwise. Fill each roll generously with shredded beef. Top with cheese slice if desired.
07 - Arrange assembled sandwiches on baking sheet. Broil 2-3 minutes until cheese is melted and bubbly. Watch closely to prevent burning.
08 - Transfer sandwiches to plates. Ladle hot cooking liquid into small bowls. Serve immediately for dipping.