Bring about an inch of salted water to a boil. Place the beans in a steaming basket and set over the boiling water. Cover and steam until tender to the bite, 3 to 5 minutes (depending on how crisp or tender you like them)
As soon as beans are ready, plunge them in a bowl of icy cold water to stop the cooking and preserve their lovely bright green color, then drain and pat dry.
Add the cooked beans, as well as the rest of the ingredients, to a large mixing bowl and toss delicately until well combined
This salad can be served immediately but will keep well for a couple of days in the refrigerator.