Pre heat oven to 350
Line a cookie sheet with foil and coat with nonstick spray.
Cut the celery, carrot and green onion into large chunks and throw into a food processor.
Pulse to chop into small bits.
In a large bowl, combine the vegetable mixture, chicken, egg, breadcrumbs, garlic powder, salt, 1/2 the hot sauce and the blue cheese.
Gently fold together to combine, but don't overmix.
Form the mixture into small meatballs - you should get about 28 small meatballs.
Place the meatballs on the cookie sheet.
Bake for 20 minutes.
While the meatballs are baking, put the rest of the hot sauce and the butter into a microwave safe dish.
Microwave about 30 seconds, until butter melts.
Stir well to combine.
Remove the meatballs from the oven and allow to cool for a few minutes.
Place the meatballs onto a serving dish and drizzle with butter/hot sauce mixture.