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 turn a deep golden brown and are fully caramelized, approximately 25 to 30 minutes. During the final 2 minutes, stir in the minced garlic. Remove from heat and let the mixture cool completely.
02 - In a mixing bowl, combine the sour cream, mayonnaise, softened cream cheese, Worcestershire sauce, onion powder, garlic powder, salt, and freshly ground black pepper. Stir until the mixture is smooth and all ingredients are evenly blended.
03 - Gently fold the cooled caramelized onion mixture into the creamy base. Stir thoroughly to ensure even distribution throughout the dip.
04 - Cover the bowl tightly and refrigerate for at least 1 hour to allow the flavors to meld together. For the best results, refrigerate overnight.
05 - Before serving, give the dip a good stir. Garnish with finely chopped chives or green onions if desired. Serve chilled alongside potato chips, pretzels, or an assortment of fresh crudités.