Cut the onions into small slices, then melt the butter in a pan on a medium heat. Add the onions and some salt and stir until golden-brown. Allow to cool down.
Mix cream cheese, sour cream, chives and onions in a bowl and add salt and pepper to taste.
You can make a tasty variation of this recipe by adding other ingredients. A teaspoon of tomato paste will turn it a nice red colour, pesto will make it smooth and green.