Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper for easy cleanup.
Cut the chicken breast into 1-inch bite-sized pieces and chop the broccoli, bell peppers, and zucchini into similar uniform sizes to ensure even cooking.
In a small mixing bowl, whisk together the extra virgin olive oil, lemon juice, dried oregano, garlic powder, sea salt, and black pepper to create the marinade.
Place the diced chicken and chopped vegetables onto the prepared sheet pan and pour the lemon-herb marinade over the top.
Toss the ingredients thoroughly with your hands or tongs until everything is evenly coated, then spread them out into a single layer across the pan.
Roast in the center of the oven for 18 to 22 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are tender with slightly charred edges.
Remove from the oven and serve immediately, garnished with fresh herbs or an extra squeeze of lemon if desired.