Place the cubed potatoes in a large pot and cover with cold water by about an inch. Add 1 teaspoon of salt to the water.

Bring to a boil over high heat, then reduce to a simmer. Cook for 12-15 minutes, or until potatoes are tender when pierced with a fork but not falling apart.

While potatoes cook, prepare the dressing. In a medium bowl, whisk together mayonnaise, sour cream, Dijon mustard, white wine vinegar, black pepper, and garlic powder until smooth.

Drain the cooked potatoes in a colander and spread them out on a baking sheet to cool completely. This helps prevent them from becoming mushy when mixed.

Once potatoes are cool, transfer them to a large mixing bowl. Add the chopped celery, red onion, dill, parsley, and chives.

Pour the dressing over the potato mixture. Using a rubber spatula or large spoon, gently fold everything together until evenly coated. Be careful not to overmix and break the potatoes.

Taste and add additional salt if needed. Cover the bowl and refrigerate for at least 1 hour before serving to allow flavors to meld.

Before serving, give the salad a gentle stir and adjust seasoning if necessary. Garnish with additional fresh herbs if desired.