In a small bowl, mix together all the dressing ingredients and set aside.
Bring a large saucepan of salted water to a boil and prepare a large bowl of ice water.
Plunge the green beans into the boiling water for 2 minutes.
Drain the beans and immediately plunge them into the ice water to stop the cooking process.
Drain the beans and dry them with a clean cloth to remove the excess water.
Mix all the ingredients together and add the dressing to taste. Pour the dressing on the salad a maximum of 30 minutes before serving. Do not do this last step too far in advance because the acidity of the dressing will cause the green beans to lose their vibrant green colour.