Preheat your oven to 400°F and line a large rimmed sheet pan with parchment paper for easy cleanup.
Cut the chicken breast into 1-inch bite-sized pieces and peel and cube the sweet potato into small half-inch chunks.
Place the chicken pieces, cubed sweet potatoes, and broccoli florets into a large mixing bowl.
In a small jar or bowl, whisk together the extra virgin olive oil, lemon juice, lemon zest, dried oregano, garlic powder, sea salt, and black pepper.
Pour the lemon-herb dressing over the chicken and vegetables, tossing thoroughly to ensure every piece is evenly coated.
Spread the mixture in a single layer on the prepared sheet pan, ensuring no pieces are overlapping so they roast rather than steam.
Bake for 20 to 25 minutes, or until the chicken is cooked through and the sweet potatoes are fork-tender with slightly caramelized edges.
Remove from the oven and let the pan rest for 5 minutes before serving to allow the juices to redistribute.