Caramelize Onions: (This step could be done in advance. Store caramelized onions in fridge until ready to use). Heat butter and oil in a sauté pan over low heat. Add onions. Cook, stirring every few minutes, for about 30 minutes, until caramelized and deep rich golden color. Remove to bowl to cool.

Make Dip: In a mixing bowl add Greek yogurt, sour cream, mayo, garlic, chives and salt. Stir in caramelized onions. Taste and add salt and pepper, as needed. (I like to reserve a pinch of chives and caramelized onions to add on top of the dip before serving.) Refrigerate for at least 30 minutes before serving to allow the flavors to blend.

Serve with dipping items like ruffles or kettle potato chips, pretzel thins, pita bread, crackers, or veggies. Use leftover dip as a condiment for burgers or sandwiches. Leftovers will keep in the fridge for 5 days.