4 Hamburger buns
4 slices provolone
Freshly ground black pepper
kosher salt
1 tbsp. brown sugar
1 tbsp. Worcestershire sauce
2 tbsp. ketchup
1/2 c. beef broth
1 lb. ground beef
1 Garlic clove, minced
2 bell peppers, chopped
1 onion, chopped
1 tbsp. vegetable oil