Heat large nonstick skillet over medium heat until hot. Add onion, cook 3 to 5 minutes until golden brown. Add ground beef and bell pepper; cook 8 to 10 minutes, breaking beef into 1/2-inch crumbles and stirring occasionally.
Stir in tomato sauce, barbecue sauce, ketchup, Worcestershire sauce, brown sugar and mustard; increase heat to medium-high. Bring to a boil; cook 5 to 10 minutes or until sauce is thickened, stirring occasionally. Season with salt, as desired.
Divide beef mixture evenly among buns. Top with pickles, coleslaw and cheese, if desired. Close sandwiches.
Nutrition information per serving: 285 Calories; 81 kcal Calories from fat; 9 g Total Fat; 3 g Saturated Fat; 3 g Monounsaturated Fat; 84 mg Cholesterol; 460 mg Sodium; 26 g Total Carbohydrate; 3.1 g Dietary Fiber; 28 g Protein; 4.5 mg Iron; 7.8 mg Niacin; 0.7 mg Vitamin B6; 2.8 mcg Vitamin B12; 6.9 mg Zinc; 22.1 mcg Selenium; 112.1 mg Choline;