Preheat your oven to 300°F (150°C).
Season the beef roast with salt and pepper.
In a large skillet, heat olive oil over medium-high heat.
Sear the beef on all sides until browned, about 3-4 minutes per side.
Place the seared beef in a slow cooker.
Add sliced onion, minced garlic, Worcestershire sauce, and beef broth to the slow cooker.
Cover and cook on low for 4 hours, or until the beef is tender.
Once cooked, remove the beef and shred it with two forks.
Strain the broth to serve as au jus.
Toast the rolls and fill with shredded beef and pickles, then serve with au jus on the side.