Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper for easy cleanup.
Pat the chicken breast completely dry with a paper towel to ensure the skin or surface gets a beautiful golden-brown sear.
In a small bowl, whisk together the olive oil, minced garlic, dried rosemary, dried thyme, sea salt, and black pepper.
Place the chicken breast on one side of the baking sheet and the trimmed asparagus on the other side.
Drizzle the herb oil mixture over both the chicken and the asparagus, using your hands or a brush to coat everything evenly.
Slice the half lemon into thin rounds and layer them directly on top of the chicken and asparagus spears.
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 asparagus is tender.
Remove from the oven and let the chicken rest for 5 minutes before slicing to keep the juices locked in.