Combine first 6 dressing ingredients and whisk. Then add oil and re-whisk and set aside.
Boil potatoes until almost tender; add beans and cook until potatoes are fork tender. Rinse under cold water to stop cooking process ‚Äö?Ñ?¨ drain well. Once cooled, add to large bowl with onions and most of the dressing. Toss gently so as not to break up potatoes. Chill covered in fridge at least 1 hour. Remove and let come to room temperature before serving. Add remaining dressing and olives and serve.