01 - Heat a large skillet over medium-high heat. Add the ground beef and cook, breaking it apart with a spatula, until browned and no longer pink, approximately 5–7 minutes. Drain excess fat if necessary.
02 - Add the chopped onion, bell pepper, and garlic to the skillet with the beef. Sauté for 3–4 minutes until vegetables are softened and fragrant.
03 - Pour in the tomato sauce, then add tomato paste, ketchup, Worcestershire sauce, mustard, brown sugar, smoked paprika, chili powder, salt, and pepper. Stir thoroughly to combine all ingredients.
04 - Reduce heat to low and let the mixture simmer uncovered for 8–10 minutes, stirring occasionally, until the sauce has thickened and flavors have melded together.
05 - While the beef mixture simmers, melt butter in a separate skillet or on a griddle over medium heat. Place the buns cut side down and toast until golden brown, about 1–2 minutes.
06 - Generously spoon the sloppy joe mixture onto the toasted buns. Add optional pickles or shredded cheese if desired. Serve immediately while hot.