1. If using whole tomatoes, cut them into smaller pieces.
2. In large pot, brown ground beef and onion; drain off fat.
3. Add tomatoes and 6 cups water; bring the mixture to boil.
4. Reduce heat and simmer for about 20 minutes.
5. Bring it to boil again and add orzo and vegetables.
6. Reduce heat; add salt and pepper to taste and simmer for another 20 minutes
7. Arrange the orzo in individual serving plates and sprinkle with chopped parsley.