Begin by heating the olive oil in a large skillet over medium heat. Once the oil is shimmering, add the thinly sliced onions along with the salt and sugar. The sugar will help to caramelize the onions, enhancing their sweetness.
Cook the onions, stirring occasionally, for approximately 25-30 minutes. Keep a close eye on them to prevent burning; if they begin to brown too quickly, reduce the heat. You want the onions to become soft, golden brown, and deeply caramelized.
Once the onions have reached a beautiful caramelized state, remove the skillet from the heat. Allow the onions to cool slightly while you prepare the dip mixture.
In a mixing bowl, combine the softened cream cheese, sour cream, garlic powder, dried thyme, and Worcestershire sauce (if using). Using a spatula or an electric mixer, blend the ingredients until the mixture is smooth and creamy.
After the onions have cooled, carefully fold them into the cream cheese mixture, ensuring they are evenly distributed throughout the dip.
Transfer the delicious dip to a serving bowl, then cover and refrigerate for a minimum of 30 minutes. This chilling time allows the flavors to meld together beautifully.
Just before serving, garnish the dip with a generous sprinkle of freshly chopped chives for a pop of color and flavor.