Preheat your oven to 400°F (200°C) and line a large rimmed sheet pan with parchment paper for easy cleanup.
Cut the chicken breast into 1-inch bite-sized pieces and chop the sweet potato into small cubes to ensure even cooking.
Slice the zucchini into half-moons and roughly chop the red bell pepper into 1-inch pieces.
In a small mixing bowl, whisk together the extra virgin olive oil, fresh lemon juice, dried oregano, garlic powder, sea salt, and black pepper.
Arrange the chicken pieces, broccoli florets, sweet potato, zucchini, and bell pepper on the prepared sheet pan in a single layer.
Drizzle the lemon-herb oil mixture over the chicken and vegetables, then use your hands or tongs to toss everything until thoroughly coated.
Roast in the center of the oven for 20 to 25 minutes, or until the chicken is cooked through and the sweet potatoes are fork-tender.
Remove from the oven and serve immediately while hot, adding an extra squeeze of fresh lemon if desired.