Step 1: Season the chuck roast generously with salt and pepper. Heat olive oil in a large skillet over medium-high heat and sear the roast on all sides until a deep brown crust forms.
Step 2: Place the sliced onions and minced garlic at the bottom of the slow cooker, then place the seared roast on top.
Step 3: In a small bowl, whisk together the beef broth and Worcestershire sauce, then pour the mixture over the roast in the crockpot.
Step 4: Cover and cook on low heat for 7 to 8 hours (or high for 4 hours) until the beef is tender and easily pulls apart with a fork.
Step 5: About 45 minutes before serving, add the sliced bell peppers to the slow cooker so they soften but maintain some texture.
Step 6: Remove the beef from the slow cooker and shred it using two forks. Return the shredded beef to the juices to keep it moist.
Step 7: Pile the beef and pepper mixture onto toasted hoagie rolls, top with two slices of provolone cheese, and broil in the oven for 1-2 minutes until the cheese is melted.