The grated celery and beetroot are placed in a bowl. Then add the remaining ingredients and mix thoroughly with your bare hands. Yotam Ottolenghi, who has a very special relationship with vegetables, calls this process "massaging".
This, according to his thesis, makes the vegetables take on the aromas better. If you like, you can taste the salad at the end with salt, pepper, sugar and vinegar - you may need a little more than what is indicated in the list of ingredients.
The whole thing should then be left to stand for about an hour, so that the salad tastes like something. You can also keep the salad in the fridge for two days and add a little bit of the fresh herbs just before you eat, because of the beautiful sight of it.