Preheat oven to 400°F and line a large baking sheet with parchment paper.
Peel and dice the sweet potato into 1/2-inch cubes and slice the carrots into rounds.
Cut the chicken breast into bite-sized pieces of uniform size for even cooking.
In a large mixing bowl, whisk together the olive oil, lemon juice, dried oregano, garlic powder, sea salt, and black pepper.
Add the chicken, sweet potato cubes, carrot rounds, and broccoli florets to the bowl and toss until thoroughly coated.
Spread the ingredients in a single layer on the baking sheet, ensuring they are not overcrowded.
Roast for 22 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are tender.