Rub roast with olive oil, salt and pepper and then coat with Italian Seasoning. Place roast in zip lock bag and add red bell pepper and onion, pour in all of the peppercini peppers including all of the juice from the jar. Seal bag and roll around to ensure roast is coated with liquid. Place in refridgerator overnight. The next morning pour contents of bag into crock-pot and cover with the beef broth. Place crock-pot on low and let cook all day or at least 6 to 8 hours.
Take roast out of crock-pot and place on dish. Place large bowl with a colander in it in sink. Pour all liquid and veggies into colander so the colander catches the veggies and the bowl catches the juices. Strain colander and pour veggies out on a cutting board, they will be mush but chop them up with knife. Place in a bowl and set aside. Use fork to shred meat. Put meat in serving bowl and pour juice over it. Let stand for 15 mins. Then place meat on bun warmed in oven and then top with spoonfull or two of veggies and top with mozzorella cheese.