Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper for easy cleanup.
Cut the chicken breast into 1-inch bite-sized pieces and halve the baby potatoes.
Place the chicken pieces, halved potatoes, broccoli florets, and sliced red bell pepper onto the prepared baking sheet.
In a small bowl, whisk together the olive oil, lemon juice, dried oregano, garlic powder, sea salt, and black pepper.
Drizzle the lemon-herb mixture over the chicken and vegetables, tossing thoroughly with your hands or tongs to ensure an even coating.
Spread the ingredients out in a single layer, ensuring the chicken and potatoes aren't overcrowded so they roast and crisp up properly.
Roast in the oven for 20 to 25 minutes, or until the chicken is cooked through and the potatoes are fork-tender.
Remove from the oven and serve immediately, optionally garnished with fresh parsley or an extra squeeze of lemon.