01 -
Melt butter with olive oil in a sauté pan over low heat. Add onions and cook, stirring occasionally, for about 30 minutes until deeply caramelized and golden. Transfer to a bowl and let cool. This step can be prepared in advance and refrigerated.
02 -
Combine Greek yogurt, sour cream, mayonnaise, minced garlic, chopped chives, and kosher salt in a mixing bowl. Stir in the cooled caramelized onions until evenly incorporated.
03 -
Adjust seasoning with additional salt and freshly cracked black pepper to taste. Optionally reserve some chives and caramelized onions for garnish. Cover and refrigerate for at least 30 minutes to meld flavors.
04 -
Serve chilled with potato chips, pretzel thins, pita bread, crackers, or vegetable crudités. Use leftovers as a flavorful condiment for sandwiches or burgers. Store refrigerated and consume within 5 days.