Preheat oven to 450 degrees.
Add the olive oil to a cast iron skillet and wipe with a paper towel, coating the surface of the skillet evenly. Set aside.
In a small saucepan, add the buffalo sauce and butter. Cook over low heat, whisking until the butter has melted and is fully incorporated into the buffalo sauce.
Remove from heat and allow mixture to cool for about 10 minutes.
In large mixing bowl, combine the ground chicken, egg, celery, bread crumbs, blue cheese, salt, and hot sauce mixture. Mix everything together by hand.
Form the meatball mixture into mini meatballs that are about 3/4-inch in size.
Place balls into the cast iron skillet, making sure they sit snugly together.
Bake the meatballs for about 20 minutes, or until they're cooked through.
When the meatballs are just about done, lightly brush them with a little more buffalo sauce, if desired.
Allow the meatballs to cool slightly before serving.
Serve with blue cheese dressing and celery sticks.