Start by boiling the Yukon gold potatoes to achieve that perfect fluffy interior. Place the cubed potatoes into a large pot and cover them with cold water, adding 1 tablespoon of kosher salt. Bring the water to a boil over high heat, then reduce to medium-high and simmer until the potatoes are tender, which should take about 12 to 16 minutes. Drain the potatoes and set them aside to cool slightly.
Next, preheat your oven to 400°F (200°C). In a large bowl, toss the drained potatoes with olive oil, garlic powder, and freshly cracked black pepper. Spread the potatoes evenly on a baking sheet and roast them for about 30 minutes, flipping halfway through to ensure even cooking.
While the potatoes are roasting, combine the sour cream and mayonnaise in a mixing bowl. Stir in the Dijon mustard, lemon juice, and a hint of salt and pepper. Toss in the chopped scallions, fresh dill, and parsley. Blend everything well until creamy.
Once the potatoes are roasted, place them into a large serving bowl and toss them with the creamy dressing until all pieces are coated.
Garnish with reserved scallions, dill, and parsley before serving warm or at room temperature.
