Start by patting your boneless chuck roast dry with paper towels, ensuring it’s moisture-free for better browning. Generously season all sides with kosher salt and black pepper, allowing the flavors to deeply penetrate the meat.

In a large cast-iron skillet, heat olive oil over medium-high heat until shimmering. Carefully place the seasoned roast into the pan and sear for approximately 5 minutes on each side, or until a golden-brown crust forms.

Once the roast is beautifully browned, transfer it to a slow cooker, scraping any flavorful drippings from the skillet into the pot.

Dot your seared roast with several pats of unsalted butter. Sprinkle ranch dressing mix and French onion soup mix evenly over the roast. Arrange whole pepperoncini peppers around the roast.

Cover the slow cooker with its lid and set it to cook on HIGH for 5 hours or on LOW for 7 hours. Resist the temptation to lift the lid.

Once your Mississippi Pot Roast is cooked to perfection, use two forks to shred the tender meat directly in the slow cooker. Mix the shredded meat with the flavorful cooking juices.