Preparation Steps

• In a large skillet over medium heat, melt the butter. Add the sliced onions, salt, and sugar. Cook, stirring occasionally, until onions are soft and deeply golden brown, about 35–40 minutes.
• If using wine, add it to the pan and cook until almost completely evaporated, about 2 minutes. Remove from heat and let cool slightly.
• In a mixing bowl, combine the cooled caramelized onions, sour cream, mayonnaise, thyme, black pepper, and garlic powder. Stir until smooth and well combined.
• Transfer the dip to a serving bowl, cover, and refrigerate for at least 1 hour before serving to allow flavors to meld.