In a large saute pan, heat the oil over medium-low heat, add the onions, saute for 5 minutes. Add the peppers and cook for 5 minutes more. Stir in the garlic and marjoram, continue to cook for 2 minutes more. Transfer vegetables to a bowl with a slotted spoon and reserve. Add the meat to the pan, increase the heat to medium, and cook the meat, breaking it up with a wooded spoon, until it just loses it's color about 5 minutes. Pour excess fat from the pan and discard. Combine the meat and vegetables in the pan along with the tomato sauce, sugar, Worcestershire, vinegar, mustard, and 1/2 cup of the water. Bring the mixture to a simmer, cover, and cook for 20 minutes. (If the mixture appears to be too dry add the additional water.) Season with the salt and pepper to taste. When ready to serve divide the mixture evenly between the buns. Serve.