Preheat the oven to 450°F (230°C).

Slice the chicken and vegetables into small, uniform pieces; smaller cuts are essential to ensure the chicken cooks through within the 10-minute window.

Distribute the chicken cubes, broccoli, bell pepper, and zucchini evenly across a large rimmed baking sheet.

Drizzle the olive oil over the chicken and vegetables, then sprinkle with oregano, garlic powder, salt, and black pepper.

Toss all ingredients directly on the pan until thoroughly coated, then spread into a single, non-overlapping layer.

Place the tray in the center of the preheated oven and roast for 10 minutes, or until the chicken reaches an internal temperature of 165°F (74°C) and the vegetables are tender-crisp.

Remove from the oven and serve immediately while hot.