In a large heatproof bowl, place the green beans and cover with boiling water.
Cover bowl and let stand 10 minutes or until beans are tender.
Drain them and plunge into a pre-prepared bowl of ice water to cool them; drain again and pat dry.
Meanwhile, in another large bowl, using a whisk, combine the anchovies, shallot, oil, tarragon, vinegar and mustard.
Reserve 1/4 cup of the dressing; set aside.
To the large bowl of dressing, add the green beans, kale and cherry tomatoes; tossing gently to evenly coat.
Divide the salad among plates.
Top with eggs, tuna, olives and capers.
Drizzle with reserved vinaigrette.