In a large saucepan or Dutch oven over medium-high heat, combine beef and onion.Cook until the meat is mostly browned, about 5 minutes.Drain well.
Meanwhile, in a small bowl whisk together tomato sauce, ketchup, brown sugar, mustard, vinegar, Worcestershire, 1/4 teaspoon salt and !/8 teaspoon pepper.
Pour sauce ingredients over drained beef and stir until evenly coated.Simmer uncovered 20 minutes, stirring occasionally (cover if you prefer a sloppier Sloppy Joe).Serve on buns.
Some popular reader variations include adding finely chopped celery, bell pepper or carrots.
