In a large skillet, melt the butter and add the onions
Cook until onions are just starting to turn translucent, then add chicken and hot sauce
Stir and cook for about 3 minutes, until sauce starts to thicken a bit
Add chicken mixture to slow cooker, along with all other ingredients except for scallions
Mix well and set slow cooker to low for 2-3 hours. Stir once about halfway through cooking to make sure the cheeses are well combined with everything else
To serve, top with scallions and, if desired, additional blue cheese and hot sauce. Perfect with chips, celery, carrots, or whatever else you'd like to dip!