Peel the celery root and cut them into pieces the size and shape of a match stick. Boil until soft, then drain and place in a dish. Finely crush or blend the nuts. Soak the white bread in water, then squeeze in the palms of the hands to expel all the water, and add it to the crushed nuts. Then add the salt, crushed garlic, olive oil and vinegar. Mix. Finally add the yoghurt. Mix well again. Pour this sauce over the celery. Sprinkle with chopped parsley, salt and red pepper. Decorate with a few olives.