01 - In a large skillet, melt butter and olive oil over medium heat. Add the finely chopped onions along with a pinch of salt. Cook, stirring frequently, until the onions are golden brown and deeply caramelized, about 25 to 30 minutes. During the last 2 minutes, stir in the minced garlic. Remove from heat and let cool completely.
02 - In a mixing bowl, combine the sour cream, mayonnaise, softened cream cheese, Worcestershire sauce, onion powder, garlic powder, salt, and black pepper. Stir until the mixture is smooth and all ingredients are thoroughly blended.
03 - Fold the cooled caramelized onion mixture into the creamy base. Mix well to ensure even distribution throughout the dip.
04 - Cover the bowl and refrigerate for at least 1 hour to allow the flavors to meld together.
05 - Before serving, give the dip a good stir. Garnish with freshly chopped chives or green onions if desired. Serve chilled alongside potato chips, pretzels, or an assortment of fresh vegetables.