Preheat the oven to 350 degrees F and prepare a small, 1 quart baking dish for cooking by spraying with non stick spray.
Reserve a small amount of the cheddar and blue cheese for the top of the dip.
Make the dip
In a large bowl, use an electric mixer on low speed to mix together the chicken, cream cheese, remaining cheddar cheese, remaining blue cheese, hot sauce and ranch dressing.
Spread the dip in the prepared bowl and top with the remaining cheeses and green onions.
Add an extra drizzle of ranch and hot sauce.
Bake
Bake for 20 minutes or until heated throughout.
Serve
Serve with chips, pretzels and celery.
Notes
For easy clean-up and in case of spillage, place a sheet of foil or a baking sheet under the baking dish.
For the chicken - simply use some leftover rotisserie chicken, or poach a couple of chicken breasts until cooked, then shred.
Substitutions
To make this dish less spicy, use less hot sauce.
You can use hot sauce in place of the buffalo sauce, if desired.
Use blue cheese dressing instead of ranch.
Making ahead and reheating
This dish is best served fresh from the oven, however, you can make ahead and warm it up. I find it warms up best in the microwave, but if reheating in the oven be sure to cover with foil and cook on low temp to prevent browning on the top.
Adapting for the Slow Cooker
Make the dip as written, reserving the extra cheddar and blue cheese crumbles. Place in a small "dipper" sized crock pot. Heat on low, or keep warm as needed.
About 30 minutes before serving - top with the remaining shredded cheese and blue cheese on top and green onions.
What to do with leftovers
Store in a covered container in the refrigerator for up to 4 days. Reheat to piping hot!