Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper for easy cleanup.
Cut the chicken breast into 1-inch bite-sized pieces and halve the baby potatoes so they cook quickly.
Chop the broccoli into small florets and slice the red bell pepper into 1-inch wide strips.
In a small mixing bowl, whisk together the extra virgin olive oil, fresh lemon juice, dried oregano, garlic powder, sea salt, and black pepper.
Place the chicken, potatoes, broccoli, and peppers onto the prepared sheet pan.
Drizzle the lemon-herb marinade over the ingredients and toss thoroughly with your hands or tongs to ensure everything is well-coated.
Spread the mixture into a single, even layer across the pan to allow for proper roasting and browning.
Bake for 20 to 25 minutes, or until the chicken reaches an internal temperature of 165°F and the potatoes are fork-tender and golden.