Bring water, salt, and potatoes to a boil then reduce heat to simmer for 15 minutes. In the meantime, make the dressing.
In a small or cup combine: parsley, garlic, evoo, red wine vinegar, lemon, oregano, salt and pepper. Mix well.
Add string beans to boiling pot and let them continue to boil for another 5 more minutes.
Strain the string beans and potatoes and place into a large mixing bowl. Pour the dressing over it while it is still hot and lightly toss to combine.
Optional: if you want to add some sliced red onion, it goes well with it also.