Season the chuck with salt and pepper. Brown it in the oil in a hot skillet for 4 minutes per side and place it in a 6-quart slow cooker.
Whisk the broth with oregano, basil, garlic powder, onion powder, red pepper flakes and Worcestershire. Pour it around the beef.
Scatter the bell peppers and pepperoncini around the roast and add the brine.
Cover and cook on low for 8 hours, until the beef is very tender. Rest it for 10 minutes, then slice thinly across the grain or shred into large pieces.
Return the beef to the juices for 10 minutes. Split the rolls, add the beef and peppers, and spoon on enough cooking liquid to moisten without soaking through.