Heavily season all sides of the beef with salt. Allow to sit in refrigerator uncovered overnight or for up to 24 hours.
Remove from fridge and allow it to come to room temperature, about 30 minutes - 1 hour. Heat a cast iron skillet over medium high heat. Once hot, add oil and sear beef on all sides.
Remove from heat. Place beef broth, Italian seasonings, garlic, bay leaves, and pepperoncini in your crock pot and gently mix. Add in beef.
Cook on low for 9 - 10 hours or on high for 3 - 4.
When finished cooking, remove the beef and shred. Pour and strain the broth into a container and taste to adjust seasoning if need be.
Load rolls up with beef, giardiniera, and red peppers. Dunk the sandwiches in the broth.