Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper for easy cleanup.
Pat the chicken breast completely dry with a paper towel to ensure the exterior becomes perfectly crispy during roasting.
In a small mixing bowl, whisk together the olive oil, finely chopped fresh rosemary, sea salt, black pepper, and lemon juice.
Place the chicken breast, broccoli florets, and sliced carrots onto the prepared baking sheet in a single layer.
Drizzle the herb-lemon oil over the chicken and vegetables, using your hands or a brush to coat everything thoroughly.
Roast for 20 to 25 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are tender with slightly charred edges.
Allow the chicken to rest for 5 minutes before slicing and serving over a bed of warm, fluffy quinoa.