

Season the roast generously with salt and pepper. Heat olive oil in a large skillet over medium-high heat and sear the beef on all sides until nicely browned, about 3–4 minutes per side.
Place the sliced onion and garlic in the bottom of the slow cooker, then add the seared roast. Pour in the beef broth and Worcestershire sauce, sprinkle with thyme, and cover. Cook on HIGH for 4-5 hours, until the beef is fork-tender.
Remove the roast from the slow cooker and let it rest for a few minutes before shredding with two forks. Strain the cooking liquid through a fine-mesh strainer into a saucepan or bowl, pressing lightly on the onions to release their juices. Season the au jus with salt and pepper and place in saucepan over low heat to keep warm for serving.
Preheat the broiler. Split, but do not separate the rolls, pile each with the shredded beef and top with 2-3 slices of provolone cheese. Place each open sandwich on a baking sheet and broil for 1 to 2 minutes, until the cheese is melted and bubbling.
Serve warm with a side of au jus for dipping.