Place the ham bone into a large pot and fill with enough water to cover. Bring to a boil and cook for 15 minutes. Add the onion and tomatoes, then stir in the frozen mixed vegetables and potatoes. Simmer for about 20 minutes, then add the macaroni, rice, and chopped ham. Cover and simmer over medium-low heat for 1 1/2 hours. Any ham on the bone should come off easily. Stir in the tomato sauce and let cool for about 15 minutes before serving.
