Kartoffelsalat (German potato salad)

For ➍
3 medium russet potatoes, scrubbed but not peeled
3 tbs white onion, finely chopped
½ apple, chopped
1 stalk celery & leaves, very thinly sliced
2 dill pickles, chopped
½ tbs sweet pickle relish, heaped
1 ts sugar
½ tbs cider vinegar
½ tbs pickle juice
½ tbs extra virgin olive oil
¾ ts yellow mustard
6 tbs mayonnaise
¼ ts salt
¼ ts ground black pepper
¾ tbs parsley, finely chopped
2 hardboiled eggs
½ tomato, slices for garnish (or grape tomatoes or cherry tomatoes)
½ torn lettuce leaf, for garnish
½ paprika, for garnish

In a large covered pot, bring potatoes to a boil in enough salted water to cover by at least 2 cm. Lower heat to a simmer, and cook about 25-30 m or until potatoes are tender when pierced with a fork, but still firm. Drain potatoes in colander, and briefly run cold water over the potatoes. Transfer drained potatoes back into the empty covered pot and set on a very low flame for  2 m or two, being careful not to scorch them. This will help to dry the potatoes and to ensure that they are not wet or soggy. Return potatoes to colander, and let them cool to the touch.
Peel and then slice the potatoes into 2.5 cm pieces.
In a large bowl, stir together the onions, apples, celery, dill pickles, sweet relish, and ⅔ of the chopped parsley.
In a separate bowl, whisk together the sugar, vinegar, pickle juice, olive oil, mustard, mayonnaise and the salt and pepper. Pour over the onion mixture, stirring well to coat evenly.
Add the potatoes and 1 chopped hardboiled egg. Fold and stir gently to combine. Transfer to a wide and shallow serving dish.
Garnish with 1 quartered hardboiled egg, tomato slices and the torn lettuce. Sprinkle with remaining parsley and the paprika.

Cover and keep refrigerated until serving time.
Serve f.i. with Königsberger Klopse.