01 - In a large skillet over medium heat, melt butter with olive oil. Add chopped onions and cook, stirring frequently, until golden brown and caramelized, approximately 20 to 25 minutes. Reduce heat if onions begin to burn. Remove from heat and allow to cool to room temperature.
02 - In a mixing bowl, combine sour cream, mayonnaise, and softened cream cheese. Whisk until smooth and homogeneous.
03 - Add caramelized onions, garlic powder, onion powder, salt, black pepper, and cayenne pepper if using to the bowl. Mix until thoroughly combined.
04 - Stir in chopped chives. Taste and adjust seasoning as needed.
05 - Cover and refrigerate for at least 1 hour to allow flavors to meld and develop.
06 - Before serving, garnish with additional chives. Serve chilled with potato chips, crackers, or fresh vegetables.