Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper for easy cleanup.
Slice the sweet potato into thin wedges and chop the broccoli and carrots into bite-sized pieces.
In a small bowl, whisk together the olive oil, lemon juice, lemon zest, rosemary, garlic powder, salt, and pepper.
Place the chicken breast on one side of the pan and the vegetables on the other, then drizzle the lemon-herb mixture over everything.
Toss the vegetables to coat evenly and rub the marinade into the chicken to ensure maximum flavor.
Roast for 20-25 minutes, or until the chicken reaches an internal temperature of 165°F and the sweet potatoes are golden and crispy.
Let the chicken rest for 5 minutes before slicing to keep it juicy, then serve immediately.