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 25–30 minutes. During the last 2 minutes, stir in the minced garlic. Remove from heat and let the mixture cool completely.
02 - In a large 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 fully incorporated.
03 - Gently fold the cooled caramelized onion mixture into the creamy base, stirring until evenly distributed throughout the dip.
04 - Cover the bowl tightly and refrigerate for at least 1 hour to allow the flavors to meld and the dip to firm up.
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 vegetables.