Place the beef chuck roast in the slow cooker.
In a medium bowl, combine beef broth, water, Worcestershire sauce, soy sauce, dried Italian seasoning, garlic powder, onion powder, crushed red pepper flakes, salt, and black pepper. Stir well to mix.
Pour the mixture over the beef in the slow cooker.
Add the sliced green bell pepper and onion on top of the beef.
Cover and cook on low for 8 hours, or until the beef is tender and easily shredded with a fork.
Remove the beef from the slow cooker and shred it using two forks.
Return the shredded beef to the slow cooker and stir to combine with the juices and vegetables.
Slice the Italian hoagie rolls lengthwise, without cutting all the way through.
Fill each roll generously with the shredded beef and peppers mixture.
Serve warm and enjoy your Slow Cooker Melissa Jo Italian Beef sandwiches.