Wash potatoes, carrots, celery root and parsley root (do not peel), Place in a steamer or pot, cover with water, salt and cook covered until tender for about 30-40 minutes. The salad tastes better if the vegetables are steamed instead of being boiled.
Strain, cool, peel and cut into small cubes, place into a large bowl. Add cut up hard boiled eggs. Peel and dice pickled cucumbers, leek and apples, add to the bowl. Add well drained and dried peas.
Season with salt and pepper to taste. Mix with mayonnaise and mustard. Salad must be refrigerated for at least 3 hours for the favors to bite through. Enjoy!