In your crockpot, whisk together soy sauce, worcestershire sauce, chili powder, rosemary, garlic powder, onion powder, thyme, and a few grinds of black pepper. Place roast into slow cooker, and flip meat to coat all sides with the soy sauce mixture. Add 1 c. water and bay leaves. Cover and cook on low heat for 6-8 hours.
Before serving, remove roast from slow cooker. Shred meat with two forks, removing any remaining pieces of fat. Set shredded meat aside.
Pour broth through wire mesh strainer into bowl or glass measuring cup for easier pouring.
Cut sandwich rolls in half lengthwise, and fill with shredded beef. If desired, place a slice of provolone on top of the meat, and heat the open sandwich under the broiler for 3-5 minutes until cheese is melted. Assemble sandwich, and cut in half diagonally for easier dipping. Serve with dipping bowl of au jus.