Season the beef generously with salt and pepper.

Mix the beef broth and Worcestershire sauce and set aside.

Heat olive oil in a skillet over medium-high heat and sear the beef on all sides until deeply browned. Transfer to the slow cooker.

In the same pan, cook onions for 5 minutes. Add garlic and cook 1–2 minutes more. Deglaze with a few tablespoons of broth, scraping the pan.

Add onion mixture, remaining broth, and bay leaf to the slow cooker.

Cook on low for 5–6 hours or high for 3–4 hours until fork-tender.

Remove beef, slice or shred against the grain.

Strain cooking liquid to create au jus; discard bay leaf.

Return beef and onions to the slow cooker with a little au jus.

Toast rolls, fill with beef and onions, top with cheese, and melt in the oven.

Serve warm with au jus for dipping.