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 halve the baby potatoes so they cook evenly.
In a large mixing bowl, whisk together the extra virgin olive oil, lemon juice, lemon zest, oregano, garlic powder, sea salt, and black pepper.
Add the chicken, halved potatoes, broccoli florets, and sliced bell peppers to the bowl, tossing thoroughly to ensure every piece is coated in the lemon-herb marinade.
Spread the mixture in a single, even layer across the prepared sheet pan, ensuring the ingredients are not overcrowded to allow for proper roasting.
Roast in the center of the oven for 20 to 25 minutes, or until the chicken is cooked through and the potatoes are golden and tender when pierced with a fork.