Blanch the Green Beans:
Bring a large pot of water to a boil. Add the green beans and cook for 3–5 minutes until just tender. Immediately transfer to a bowl of ice water to cool, then drain.

Cook the Orzo:
Refill the pot with water and bring to a boil. Add the orzo and cook for 8–11 minutes until just tender. Drain and rinse under cold water to stop the cooking.

Prepare the Corn:
Remove the husks and silk from the corn. Using a sharp knife, slice the kernels off the cob into a large bowl.

Make the Dressing:
In a small bowl, whisk together the vinegar, olive oil, shallots, Dijon mustard, tarragon, salt, and pepper. Set aside.

Assemble the Salad:
In a large bowl, toss the cooked orzo with ½ cup of the dressing. Season with additional salt and pepper as needed. Evenly layer the corn, green beans, and cherry tomatoes over the orzo.

Chill and Serve:
Cover and refrigerate the salad along with the remaining dressing until ready to serve. When serving, pour about ¾ of the remaining dressing over the salad and gently mix. Add more dressing and seasoning to taste if desired.