Wash and trim the green beans. Lightly steam for a couple of minutes so they are just al dente. Remove from steamer and leave to cool.
Place all the dressing ingredients together in a small bowl and whisk to combine. Check the flavour and add more seasoning, mustard etc if required. Add the red onion and leave it to marinate whilst the beans are cooking.
Scatter the mixed leaves on the bottom of a serving bowl. Spread a ⅓ of the red onion and dressing over the top followed by half the green beans and half the flageolet beans. Add another ⅓ of the red onion and dressing followed by the remaining green and flageolet beans.
Finish off with the remaining red onion dressing. Scatter fresh herbs and sliced almonds over the top and serve. Nastertium flowers optional.
