01 - Melt butter and olive oil in a large skillet over medium heat. Add the finely chopped onions 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 cool to room temperature.
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 completely smooth and all seasonings are evenly distributed.
03 - Gently fold the cooled caramelized onions into the creamy base. Mix thoroughly to ensure the onions are evenly dispersed 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 - Give the dip a good stir before serving. Garnish with freshly chopped chives or green onions if desired. Serve chilled alongside potato chips, pretzels, or an assortment of crudités.