Bring a large pot of salted water to a rolling boil. While the water heats, prepare an ice bath (a large bowl filled with ice and water).
Trim the green beans. Add the trimmed green beans to the boiling water and blanch for 5 minutes. You want them cooked, but still with a nice snap.
Immediately drain the green beans and plunge them into the ice bath.
Once completely cooled, drain the beans thoroughly and pat them dry.
In a bowl whisk together the extra virgin olive oil, lemon juice, minced garlic, Dijon mustard, sesame seeds, chilli flakes, salt, and black pepper until emulsified. Taste and adjust seasonings as needed.
Add the blanched and cooled beans to the dressing bowl. Toss them nicely in the dressing. Add the chopped herbs and mix one last time.
Serve green beans salad immediately, or let it chill in the refrigerator for 15-20 minutes for the flavours to meld.
Video
Notes
Make It Ahead: You can blanch the green beans and prepare the vinaigrette up to a day in advance. Store them separately in the refrigerator. Assemble the salad just before serving for the freshest taste and texture.