Heat olive oil in a large skillet over medium heat.
Add white onion and green bell pepper.
Cook for 5 to 7 minutes until softened.
Add garlic and cook for 30 seconds until fragrant.
Add ground beef to the skillet.
Break it apart with a wooden spoon.
Cook until browned.
Drain excess grease if needed.
Add tomato sauce, tomato paste, ketchup, yellow mustard, Worcestershire sauce, brown sugar, smoked paprika, garlic powder, onion powder, Cavender's Greek Seasoning, salt, black pepper, and beef broth.
Mix thoroughly until combined.
Reduce heat and simmer for 15 to 20 minutes.
Cook until the sauce reduces and clings to the beef.
Lightly toast the hamburger buns.
Pile the sloppy joe mixture onto the toasted buns.
Add cheese slices and pickles if desired.
Serve hot.