Preheat your oven to 400°F and line a large sheet pan with parchment paper for easy cleanup.
Cut the chicken breast into 1-inch cubes and chop the broccoli, bell pepper, and sweet potato into similar bite-sized pieces to ensure even cooking.
In a small bowl, whisk together the extra virgin olive oil, lemon juice, lemon zest, minced garlic, dried oregano, sea salt, and black pepper to create the marinade.
Place the chicken and chopped vegetables onto the prepared sheet pan and pour the lemon-herb mixture over the top.
Toss everything thoroughly with your hands or tongs until every piece is well-coated in the dressing, then spread into a single layer.
Roast for 20 to 25 minutes, or until the chicken is cooked through and the vegetables are tender with slightly caramelized edges.
Remove from the oven and let rest for a few minutes before serving to keep the chicken juicy.