Fill a large pot with salted water and bring it to a boil. Add the cubed Yukon gold potatoes and cook for 12–16 minutes until tender. Drain and let cool slightly.

Preheat your oven to 400°F (200°C). In a mixing bowl, combine cooled potatoes with olive oil, garlic powder, kosher salt, and black pepper. Toss to coat, then spread on a baking sheet and roast for about 30 minutes until golden brown and crispy.

While the potatoes roast, prepare the dressing by mixing sour cream, mayonnaise, chopped scallions, dill, parsley, Dijon mustard, and lemon juice in a separate bowl. Whisk until well combined, then season with salt and pepper.

Once roasted and slightly cooled, toss warm potatoes with the creamy dressing in a serving bowl.

Garnish with additional chopped scallions and fresh herbs. Serve immediately.