To assemble the cups, place a spoonful of the buffalo chicken mixture in a tortilla cup and put a little dollop of the blue cheese sour cream on top. Sprinkle with chives and serve.
In a medium-size bowl, mix the pulled chicken with the hot sauce mixture and set aside. In a small mixing bowl, mix the sour cream and blue cheese and season with salt and pepper.
Place a small sauce pot over low heat, add hot sauce. Whisk in the butter until melted (the sauce will have an orange color).