In a large skillet over medium heat, add ground chicken. Cook until it’s no longer pink, breaking it apart as it cooks, about 5-7 minutes. Remove the cooked chicken and set aside.
In the same skillet, add the chopped onion, garlic, and diced bell pepper. Sauté until the vegetables are tender, about 3-4 minutes.
Add the cooked ground chicken back to the skillet with the vegetables.
Pour in the tomato sauce, ketchup, Worcestershire sauce, brown sugar, smoked paprika, chili powder, salt, and pepper. Stir well to combine.
Reduce the heat to low and let the mixture simmer for about 10 minutes, stirring occasionally until it thickens slightly.
While the mixture is simmering, lightly toast the hamburger buns in a toaster or on a dry skillet until golden brown.
Serve the sloppy joe mixture generously on the toasted buns and top with chopped fresh parsley for garnish.