Cut the roast into 4 large chunks. Trim the fat from the edges of each chunk and transfer them to the slow cooker.

In a large mixing bowl, whisk together the beef broth, salad dressing mix, and Italian seasoning. Pour the mixture over the beef in the slow cooker. Toss in the pepperoncini and ⅓ cup of the liquid from the jar.

Cover, and cook on LOW for 8 to 10 hours or on HIGH for 4 to 5 hours. When the meat is very tender and easy to shred, turn off the slow cooker and use two forks to shred the meat into the cooking liquid.

Set your oven to BROIL. Split open and spread the sandwich rolls with the softened butter and place them on a baking sheet. Transfer the baking sheet to the oven and toast the rolls for about 2 minutes or until just lightly toasted. Remove the baking sheet from the oven.

Use tongs to transfer the shredded beef and peppers to the toasted buns. Top each sandwich with a slice of provolone. Return the baking sheet to the oven to melt the cheese.

(For Conventional Oven Method) Preheat oven to 300 degrees F. Follow as directed, but place the ingredients in a large Dutch oven. Cover and bake for 4 ½ to 5 hours or until the meat is very tender and easy to shred. Follow as directed above to toast the buns and assemble the sandwiches.