Wash the potatoes and cut any larger baby potatoes in half so pieces are roughly uniform.

Place potatoes in a large pot and cover with cold water; add a teaspoon of salt. Bring to a boil over medium-high heat, then reduce to a simmer.

Cook until potatoes are fork-tender but not falling apart — about 12–18 minutes depending on size. Test by piercing the largest piece with a fork.

Drain in a colander and let cool slightly. For firmer texture and slightly caramelized flavor, you can roast the potatoes instead at 425°F (220°C) for 18–25 minutes until golden and tender.

In a medium bowl, whisk together mayonnaise, sour cream (or Greek yogurt), Dijon mustard, pickle juice, sugar or honey, a pinch of salt, and black pepper until smooth.

In a large mixing bowl, combine warm (not hot) potatoes, chopped dill pickles, pickle relish (if using), diced celery, green onions, and chopped fresh dill.

Pour the dressing over the potato mixture and gently fold with a rubber spatula to coat. Adjust seasoning as necessary.

Chill at least 1 hour before serving to let flavors marry. For best flavor, refrigerate for 3–4 hours or overnight.