Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper for easy cleanup.
Slice the chicken breast into even 1-inch strips and chop the broccoli, carrots, and bell peppers into bite-sized pieces.
In a small bowl, whisk together the olive oil, lemon juice, dried oregano, garlic powder, sea salt, and black pepper to create the marinade.
Place the chicken and vegetables on the prepared sheet pan and pour the marinade over them, tossing thoroughly to ensure every piece is well-coated.
Spread the mixture in a single layer to ensure even roasting and prevent steaming.
Roast in the center of the oven for 20-25 minutes, or until the chicken is cooked through and the vegetables are tender with slightly caramelized edges.
Remove from the oven and let the chicken rest for 2-3 minutes before serving to keep it juicy.