Prepare the Roast: Pat the chuck roast thoroughly dry with paper towels to ensure a better sear. If desired, lightly season all sides with a pinch of salt and freshly ground black pepper.

Sear for Flavor: Heat 1 tablespoon of neutral oil in a large, heavy-bottomed skillet or Dutch oven over medium-high heat until shimmering. Carefully place the prepared roast into the hot pan and sear for 3-5 minutes per side until a deep golden-brown crust forms. This step builds rich, caramelized flavor.

Layer in the Slow Cooker: Transfer the beautifully seared chuck roast to the bottom of your 6-quart (or larger) slow cooker. Ensure it fits snugly at the base.

Add the Tangy Liquid: Pour the ½ cup of pepperoncini juice directly over the roast. This liquid is essential for tenderizing the meat and infusing it with its signature tangy zest.

Sprinkle the Seasonings: Evenly sprinkle both the ranch seasoning mix and the au jus gravy mix directly over the top of the roast. These packets create the iconic savory and herbaceous flavor base.

Top with Peppers and Butter: Arrange the whole pepperoncini peppers around and on top of the roast. Distribute the pats of unsalted butter evenly over the surface. The butter slowly melts, basting the roast and adding richness.

Slow Cook to Perfection: Cover the slow cooker with its lid. Cook on the LOW setting for 8 to 10 hours, or until the roast is incredibly fork-tender and easily shreds apart. Avoid lifting the lid during cooking to maintain consistent temperature.

Shred and Combine: Once cooked, carefully remove the roast from the slow cooker to a large serving platter or cutting board. Use two forks to shred the tender meat into desired pieces, discarding any large pieces of fat. Return the shredded meat to the slow cooker and gently stir to combine with all the flavorful juices.

Serve and Enjoy (with optional Gravy): Serve the incredibly tender Mississippi Pot Roast warm, spooning plenty of the rich, savory pan juices over the meat. It pairs wonderfully with creamy mashed potatoes or egg noodles. For a thicker gravy, strain the pan juices into a saucepan, skim fat, simmer, and whisk in a cornstarch slurry until thickened.