Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper for easy cleanup.
Wash and peel the sweet potato, then cut it into thin wedges or 1-inch cubes for even roasting.
Trim the woody ends off the asparagus and mince the garlic clove finely.
In a large mixing bowl, whisk together the olive oil, lemon juice, lemon zest, minced garlic, rosemary, thyme, sea salt, and black pepper.
Add the chicken breast, sweet potato wedges, and asparagus to the bowl, tossing thoroughly until every piece is coated in the vibrant herb marinade.
Arrange the ingredients in a single layer on the prepared sheet pan, ensuring the chicken has enough space to brown properly.
Roast in the center of 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.
Let the chicken rest for 5 minutes before slicing to keep it juicy, then serve immediately alongside the roasted vegetables.