How to Make It
Fill a medium bowl with cold water and about 2 cups of small ice cubes. Add the sliced celery to the bowl and let it soak in the ice water bath for at least 10 minutes or for up to 30 minutes, until very crisp.
Meanwhile, in a bowl, whisk the olive oil with the lemon juice. Stir in the finely chopped shallot. Season the dressing with salt and pepper.
In a large bowl, toss the lettuce with 3 tablespoons of the citrus and olive oil dressing. Transfer the lettuce to a platter or plates.
Drain the sliced celery and pat dry thoroughly with paper towels. Add the celery to the large bowl and toss with the remaining dressing. Season the dressed celery with salt and pepper. Using a slotted spoon, scatter the sliced celery over the lettuce. Using a very sharp vegetable peeler, shave long strips of the pecorino cheese over the salad. Drizzle lightly with some of the remaining dressing in the bowl. Season the salad with pepper and serve.