In a large skillet over medium-high heat, brown the ground beef until fully cooked. Drain any excess fat.
Add diced onions and bell pepper to the skillet and cook until softened, about 5 minutes.
Stir in ketchup, Worcestershire sauce, and beef broth. Season with salt and pepper. Simmer for 5 minutes until the mixture thickens.
Toast your hamburger buns if you're feeling fancy (I always do).
Spoon the meat mixture onto the buns and top with provolone cheese.
Pop the sandwiches under the broiler for a minute or two until the cheese is melty and irresistible.