Place the roast into a slow cooker. Add the jar of pepperoncini peppers and half of the jar of juice (you can use more depending on your taste). Sprinkle Italian dressing mix on top of meat and peppers. Pour in your water (or beer if you choose) next. Cover, and cook on Low for 8 to 10 hours or on High for 6 to 7 hours. During the last hour, shred the meat with two forks. (Note: Meat should shred rather easily. If not, it needs to cook longer.) Serve on hoagie rolls or buns. Sandwiches can then be topped with provolone cheese if deisred or any other cheese you like. This is classically served with plain potato chips.