2Heat oil in a large skillet over medium heat. Add onion and 1/4 teaspoon of kosher salt; cook and stir until onion is caramelized and golden brown in color, about 20 minutes. Remove from the heat and let cool, 5 to 10 minutes.
3Mix sour cream, mayonnaise, garlic powder, white pepper, and remaining 1/2 teaspoon kosher salt together in a bowl.
