Heat a large skillet over medium-high heat and add butter. Once melted add the chopped onion, salt, and black pepper. Continue to cook until brown and jammy, about 30-40 minutes. Turn down the heat if your onions are getting too brown too quickly. I like to add 1 tbsp of water about half way through to help with the caramelization.
Cool the caramelized onions until they are no longer steaming hot, it's okay if they are still warm.
In a medium bowl, mix together the Greek yogurt, garlic powder, salt, pepper, and chives. Stir in the caramelized onions and store in the fridge for about 1 hour before serving.
Serve with chips, veggies, or pretzels!
Notes
You can cool the cooked onions in the refrigerator for 20 minutes before combining them with the rest of the ingredients.