Wash and peel the celery root. Peel the apple and remove the core. Cut the celery root and apple into thin matchsticks using a mandoline. If you do not have a mandoline you can use a serrated knife or a food processor fitted with a coarse grating blade.
Place the shredded celery root, apple, pomegranate seeds and toasted pistachios in a bowl.
In a bowl whisk together the olive oil, honey and white wine vinegar and season with salt and pepper.
Before serving, top the salad with the dressing, toss and sprinkle with chopped parsley