Rub the chuck roast with about a teaspoon each of salt and pepper. Sear it in a hot skillet on all sides until browned. Transfer the roast to the slow cooker.
In a large bowl, whisk together the beef broth, oregano, basil, parsley, onion powder, garlic powder, bay leaf, brown sugar, Italian dressing mix, red pepper flakes, and pepperoncini juice. Pour this mixture over the roast in the slow cooker.
Cover the slow cooker and cook on low for 8 to 10 hours or on high for 4 to 5 hours until the beef is tender.
One hour before it’s done, remove the bay leaf and shred the meat with a fork, then let it cook for the remaining time.
Serve your Slow Cooker Italian Beef as a classic Chicago-style sandwich on a hoagie roll. Top with pepperoncini, a slice of provolone, and a little au jus. Enjoy over rice or with mashed potatoes.