Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper for easy cleanup.
Cut the chicken breast into bite-sized cubes and place them in a large mixing bowl with the cauliflower florets.
Drizzle the olive oil over the chicken and cauliflower, then sprinkle with sea salt, black pepper, and garlic powder.
Toss the mixture thoroughly until every piece is evenly coated in oil and spices.
Spread the ingredients in a single layer on the prepared baking sheet, ensuring they aren't overcrowded so they roast rather than steam.
Roast for 20 to 25 minutes, flipping halfway through, until the chicken is cooked through and the cauliflower edges are golden and crispy.
In a small bowl, whisk together the Greek yogurt and lemon juice to create a smooth, cooling drizzle.
Transfer the roasted chicken and cauliflower to a clean bowl, pour the buffalo sauce over them, and toss gently to coat.
Serve the buffalo bites immediately, drizzled with the yogurt sauce and garnished with freshly chopped chives.