Prepare the Roast
1. Pat the chuck roast dry with paper towels and generously season all sides with salt and black pepper to help develop a flavorful crust and lock in juices during cooking.
2. Heat a large oven-safe Dutch oven or heavy pot over medium-high heat for 2-3 minutes until very hot, then carefully sear each side of the roast for 3-4 minutes until a deep golden-brown crust forms before removing to a clean plate.
3. In the same pot, combine the onion soup mix and ranch seasoning packets with the peperoncinis and 1/4 cup of their brine, stirring to incorporate, then scatter butter pats throughout the bottom to melt into the seasoning mixture.
4. Place the seared roast back into the pot, nestling it into the butter and seasoning mixture so it is partially surrounded by the flavorful liquid.
Braise in the Oven
1. Cover the pot with its lid and transfer to a preheated 300°F oven for 2.5 to 3 hours, checking occasionally to ensure the braising liquid hasn't evaporated completely.
2. The roast is ready when a fork easily pierces the meat and it shreds without resistance; if it still feels firm, return it to the oven for an additional 20-30 minutes.
3. Remove the pot from the oven and let the roast rest in its braising liquid for 10 minutes, then carefully skim excess fat from the surface if desired using a spoon or fat separator.
Shred and Serve
1. Using two forks or shredded meat claws, pull the roast apart directly in the pot, breaking it into tender shreds that absorb the tangy, buttery sauce.
2. For sandwiches, lightly toast hoagie rolls and place a generous portion of shredded roast on each, top with provolone cheese to melt from the heat, and drizzle with extra sauce.
3. For plated servings, place shredded roast on plates and spoon the rich pan sauce and peperoncinis over the top, finishing with fresh parsley and cracked black pepper.