Boil a large pot of water. Add the potatoes and cook until for tender. Remove the potatoes, and cool under running water to stop the cooking process. Quickly blanch the green beans in the pot of boiling water. Cool under running water with the potatoes.
whisk up the salad dressing while the potatoes are cooking, and set aside for later.
When ready to serve, arrange half of each salad ingredient on a plate or bowl and drizzle with salad dressing.