Preheat your oven to 400°F and line a large sheet pan with parchment paper for easy cleanup.
Peel and dice the sweet potato into small half-inch cubes, and chop the broccoli and red bell pepper into bite-sized pieces.
Cut the chicken breast into even 1-inch strips to ensure they cook at the same rate as the vegetables.
In a small mixing bowl, whisk together the extra virgin olive oil, lemon juice, dried oregano, garlic powder, sea salt, and black pepper.
Place the chicken, sweet potatoes, broccoli, and peppers onto the prepared sheet pan.
Drizzle the lemon-herb dressing over the ingredients and toss thoroughly by hand or with tongs until everything is evenly coated.
Spread the mixture out into a single layer, making sure the pan is not overcrowded so the vegetables roast rather than steam.
Bake for 20 to 25 minutes, or until the chicken reaches an internal temperature of 165°F and the sweet potatoes are fork-tender.
Remove from the oven and garnish with finely chopped fresh parsley before serving.