1 In a medium skillet over medium heat, brown the ground beef, onion, and green pepper; drain off liquids. 2  Stir in the garlic powder, mustard, ketchup, and brown sugar; mix thoroughly.3  Reduce heat, and simmer for 30 minutes. 4  Season with salt and pepper.irections. Prep. Cook. Ready In. 1  In a medium skillet over medium heat, brown the ground beef, onion, and green pepper; drain off liquids. 2  Stir in the garlic powder, mustard, ketchup, and brown sugar; mix thoroughly. 3  Reduce heat, and simmer for 30 minutes. 4  Season with salt and pepper.