Make the Vinaigrette salad dressing - In a large bowl, whisk the wine vinegar, Dijon mustard, salt and pepper. Slowly add the olive oil, while whisking. Set aside
Put the potatoes in a saucepan with salted water. Bring to a boil. Boil for around 6 minutes. Add the green beans, continue to boil for another 4 minutes, till the potatoes and beans are cooked. Plunge the green beans in a bowl of iced water to halt the cooking and keep them crisp. When cooled, peel and cut the potatoes in 4 pcs.
Display all the ingredients in a large platter, and serve the Vinaigrette salad dressing on the side.