Slice the cucumber thinly and sprinkle with a little salt so that they draw water. Throw away the cucumber water, otherwise the salad will be too watery. Cook the beans in a little salted water and then rinse in cold water.
Stir the vinegar and oil together, add the herbs and season with salt and pepper. You don`t have to use fresh herbs, it is also tasty with frozen herbs.
I always prepare the salad 1 day in advance, it just tastes better then.