Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Scrub the sweet potato and cut it into 1-inch cubes, then trim the woody ends off the asparagus spears.
In a small mixing bowl, whisk together the extra virgin olive oil, fresh lemon juice, minced garlic, finely chopped rosemary, sea salt, and black pepper.
Place the chicken breast, sweet potato cubes, and asparagus on the prepared baking sheet in a single layer.
Drizzle the lemon-herb oil mixture over the chicken and vegetables, tossing the produce and coating the chicken thoroughly to ensure maximum flavor.
Roast in the oven for 20 to 25 minutes, or until the chicken reaches an internal temperature of 165°F and the sweet potatoes are fork-tender and caramelized.
Remove from the oven and let the chicken rest for 5 minutes before slicing to keep the meat juicy.
Plate the sliced chicken alongside the roasted vegetables and serve immediately.