Cook and stir the meat and the onion in a large skillet until the meat is brown. Drain off the excess fat. Stir in the tomatoes (with the liquid) and remaining ingredients, stirring to break up the tomatoes. Heat to boiling, then reduce the heat and simmer, covered, stirring occasionally, until the noodles are tender, about 20 minutes. A small amount of water can be added if necessary. Serve hot.