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 red bell pepper into similar sized squares.
In a large mixing bowl, whisk together the extra virgin olive oil, lemon juice, lemon zest, dried oregano, garlic powder, sea salt, and black pepper.
Add the chicken pieces, broccoli florets, and bell peppers to the bowl and toss thoroughly until everything is evenly coated in the marinade.
Spread the mixture across the prepared sheet pan in a single layer, ensuring the pieces aren't too crowded so they roast rather than steam.
Place the pan in the oven and roast for 18 to 22 minutes, or until the chicken is cooked through and the vegetables are tender with slightly charred edges.
Remove from the oven and let rest for 2 minutes before serving to keep the chicken juicy.