Slice the Yukon Gold potatoes into large, uniform 2–3 inch chunks, keeping the skins attached to help maintain their structure during boiling. Add them to a large pot and cover completely with cold water. Stir in 1½ tsp kosher salt, then place over high heat and bring to a boil. Lower the heat to maintain a gentle simmer and cook for 30–35 minutes until the potatoes are tender enough to pierce easily with a fork but still hold together. Drain well through a colander and spread the potatoes across a baking sheet to cool for approximately 10 minutes.

As the potatoes are cooking, place the 5 eggs in a separate pot and cover them with cold water. Bring to a boil, then immediately remove the pot from heat. Cover and let the eggs sit undisturbed for 10 minutes. Transfer the eggs to an ice bath until completely cooled, then peel them. Set aside 4 eggs to chop and mix into the salad later, and reserve 1 whole egg for slicing as a garnish.

While waiting for the potatoes to cool enough to handle, prepare your vegetables and dressing. Finely dice the celery stalks, chop the green onions, and mince the fresh dill. In a small mixing bowl, combine the salad dressing, yellow mustard, celery seed, 1 tsp kosher salt, black pepper, and sugar, whisking until the mixture is smooth and all ingredients are fully incorporated.

When the potatoes have cooled just enough to touch comfortably, peel away and discard the skins—they should slip off easily. Cut the peeled potatoes into bite-sized cubes, roughly ¾-inch on each side. Transfer the cubed potatoes to a large mixing bowl and immediately pour the white vinegar over them while they remain slightly warm. This warmth helps the potatoes absorb the vinegar more effectively. Allow the potatoes to sit and marinate in the vinegar for about 15 minutes.

Add the diced celery, chopped green onions, and minced dill to the bowl with the vinegar-dressed potatoes. Toss gently to distribute. Roughly chop the 4 reserved hard-boiled eggs and add them to the bowl along with the prepared dressing mixture from earlier. Fold everything together carefully using a gentle motion to coat all ingredients evenly while avoiding breaking up the potato cubes.

Spoon the finished potato salad into a serving bowl and place it in the refrigerator. Chill for at least 1 hour to allow the flavors to meld together and the salad to become thoroughly cold. Just before you're ready to serve, slice the remaining hard-boiled egg and arrange the slices decoratively on top of the salad. Finish by sprinkling paprika over the surface for visual appeal and a hint of smoky flavor.