Preheat the oven to 400°F (200°C). Line a baking sheet with parchment paper.
In a bowl, combine ground chicken, blue cheese, onion powder, garlic powder, green onion, celery, and buffalo sauce. Form into ~1 heaping tablespoon-sized meatballs.
Toss shaved Brussels with oil and season with salt and pepper (optional).
Arrange meatballs and Brussels sprouts on the baking sheet. Bake for 20–25 minutes, until meatballs are cooked through (165°F internal temp).
Pierce the potato several times with a fork. Wrap in a damp paper towel and microwave for 5–8 minutes, flipping halfway through, until tender.
Mix Greek yogurt and ranch seasoning. Thin with a splash of milk or water until it reaches drizzling consistency.
Plate the potato, meatballs, and Brussels sprouts. Drizzle with ranch sauce and sprinkle with extra green onion if desired. Enjoy!