Combine the celery, leaves (if using), olives, and radishes in a bowl (incorporate some of the oil marinade from the olives if desired for extra flavor). Season lightly with salt to begin softening the celery.
Whisk together dressing ingredients. Adjust seasoning as desired. Toss dressing with the salad.
Enjoy immediately, or--even better--allow salad to sit for at least 30 minutes before serving.
Serve as an antipasto or as a side with sandwiches, charcuterie or cheeses.