Sear the Chuck Roast: Pat the chuck roast dry with paper towels and season generously on all sides with kosher salt and black pepper. Heat olive oil in a large skillet over medium-high heat. Sear the roast for 3 to 4 minutes per side until a deep brown, caramelized crust forms. Transfer the seared roast into your slow cooker.

Build the Savory Au Jus Broth: In the same hot skillet, sauté the sliced onions for 2 minutes to loosen browned beef bits. Stir in minced garlic for 30 seconds. Pour in beef broth, soy sauce, Worcestershire, red wine vinegar, brown sugar, oregano, and thyme, scraping up every bit of fond from the skillet bottom. Pour the entire aromatic mixture over the roast in the slow cooker. Tuck in fresh rosemary sprigs and bay leaf.

Slow Cook to Fall-Apart Perfection: Cover and cook on LOW for 8 to 9 hours (or on HIGH for 4 to 5 hours), until the beef is fork-tender and shreds effortlessly with zero resistance.

Shred Beef & Strain Broth: Transfer the roast to a cutting board. Discard bay leaf and rosemary stems. Using two forks, shred the succulent beef into bite-sized shreds, removing any remaining gristle. Skim visible surface fat from the slow cooker broth. Return about 1/2 cup of the warm au jus broth back over the shredded beef to keep it glistening and moist. Pour the remaining rich broth into individual dipping ramekins, garnishing each with fresh chives.

Toast Rolls & Melt Cheese: Preheat your oven's broiler to HIGH. Place split French rolls cut-side up on a baking sheet and spread lightly with softened butter. Broil for 1 to 2 minutes until lightly golden. Pile generous mounds of warm shredded beef onto each bottom roll, top with 2 slices of provolone cheese, and return under the broiler for 1 to 2 minutes until the cheese is bubbling, gooey, and melted.

Serve Warm with Au Jus: Close the sandwiches, slice in half diagonally, and serve immediately alongside steaming ramekins of au jus for continuous dunking!