Place your potato cubes in a large pot and cover with cold, salted water. Bring to a rolling boil and cook until they are fork-tender but still hold their shape (approx. 10 minutes). Drain them and immediately submerge them in an ice-water bath for 60 seconds to stop the cooking; this prevents "mushy" salad. Pat dry.

In a separate medium bowl, combine the mayo, Greek yogurt, mustard, vinegar, sugar, smoked paprika, and onion powder. Whisk until the dressing is silky and a light golden-orange color.

Place the cooled potatoes in a large mixing bowl. Pour your prepared dressing over them and toss gently with a rubber spatula to ensure every cube is lacquered in sauce.

Fold in the chopped eggs, diced celery, sweet relish, and half of the fresh chives. Be careful not to over-mix; you want the chunks of egg and celery to remain distinct.

Cover the bowl and refrigerate for at least 2 hours (though overnight is best). This "chilling" step is vital as the potatoes absorb the dressing and the smoky spices bloom.

Give the salad a final, gentle stir just before serving. Top with the remaining fresh chives and an extra dusting of smoked paprika for a professional finish.