Season the roast with kosher salt and black pepper on all sides. In a large cast iron skillet or skillet, heat the olive oil over medium high heat. When the oil is shimmering add the roast and cook until evenly browned and deeply seared on all sides, about 3 minutes per side.
Combine the beef broth, beef consommé, onion, Worcestershire sauce, rosemary, thyme, garlic powder, bay leaf, salt, and pepper into the slow cooker.
Add the roast and cook on LOW for 6 to 8 hours or on HIGH for 3 to 4 hours, or until the beef is tender. Time will vary depending on the size of your roast and your slow cooker. I recommend checking early to be safe.
Transfer the roast to a large cutting board. Don’t discard the sauce, you will use it for dipping the sandwiches.
Let the roast rest for 10 minutes. Use a sharp knife to thinly slice the beef. You can also shred the beef with two forks.
Preheat the broiler. Butter the top side of the rolls. Add a few slices of meat to the bottom halves of the rolls and top with the provolone cheese slices.
Broil just until the cheese is melted and bread is slightly golden brown. This will only take a couple of minutes so don’t walk away. Keep your eye on them.
To serve, place the sandwiches on a plate. Ladle the au jus sauce from the slow cooker into small bowls. Serve alongside the sandwiches. Dip the sandwiches into the sauce!