Heat the oil in a large skillet over medium heat. Season the chuck roast on all sides with salt and pepper.
Add the roast to the pan and cook until golden brown. Turn the roast over and cook until browned. Transfer to the slow cooker.
Add the dressing, 1/2 the banana peppers, 1/2 the giardiniera, stock and italian seasoning to the slow cooker.
Cover and cook the beef for 4 hours on high or 6-7 hours on low.
Remove the roast from the slow cooker and transfer to a platter. Skim the broth to remove some of the fat that floats to the top and discard. Shred the beef with two forks and return to the slow cooker. Stir to combine.
Continue cooking for 30 minutes so the beef can soak up the juices.
Serve the beef on long rolls with the reserved peppers and giardiniera. Top with cheese, if desired.
Video
Notes
The Italian Beef can be made up to 48 hours in advance. To serve you can return it to the slow cooker and reheat or just heat in the microwave.Store leftovers in an airtight container in the refrigerator.