Heat a medium pan or dutch oven over medium-high heat. Add the ground beef and cook until mostly cooked through, 4-5 minutes. Break it up into very small pieces as it cooks so that it is evenly ground.
1 ½ lb ground beef 90% lean
Add onions and bell pepper. Cook for another 3-4 minutes, until the beef is fully cooked. Use paper towels to soak up extra grease before proceeding to the next step.
1 onion, 1 red bell pepper
Add the garlic and seasonings and cook for 1 minute.
1 tablespoon garlic, 1 ¼ teaspoon smoked paprika, 1 ¼ teaspoon chipotle chili powder, ½ teaspoon salt
Add the tomato sauce, Worcestershire, dijon, and brown sugar (if using). Combine well, then reduce to med-low and simmer for 5 minutes, stirring often.
1 15 oz can tomato sauce, ¾ cup ketchup, 1 tablespoon worcestershire, 1 tablespoon dijon mustard, 1-2 teaspoon brown sugar
Serve over toasted buns.
For serving: Buns