Preheat oven to 400°F (200°C) and line a large rimmed sheet pan with parchment paper.
In a large bowl, toss the sweet potato cubes with 1 tablespoon of olive oil, salt, pepper, and half of the garlic and onion powder.
Spread the sweet potatoes in a single layer on the prepared sheet pan and roast for 15 minutes.
While potatoes roast, toss the chicken cubes in the remaining tablespoon of olive oil and the remaining garlic and onion powder.
Remove the pan from the oven, shift the potatoes to one side, and add the chicken cubes to the other side in a single layer.
Return the pan to the oven and roast for 15 to 20 minutes, or until the chicken reaches an internal temperature of 165°F (74°C).
In a small bowl, whisk together the buffalo wing sauce and melted butter until emulsified.
Drizzle the buffalo sauce mixture over the cooked chicken and sweet potatoes directly on the pan, tossing gently to coat.
Assemble the bowls by dividing the greens and sliced celery among four containers.
Top each bowl with the buffalo chicken and sweet potato mixture and garnish with blue cheese crumbles.