Over medium heat, brown the ground beef, onion, and green pepper. As the beef browns, break it into small bits. Once browned, drain off the grease leaving the meat mixture in the skillet. Next stir in the garlic powder, mustard, ketchup, and brown sugar. Mix together well and reduce the heat. Simmer uncovered for 30 minutes. Season with salt and pepper to taste.
Serve on buns with cheese slices and pickles! Yummy!!