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 and place it on one side of the prepared baking sheet.
Mince the garlic cloves and finely chop the fresh rosemary and thyme leaves.
In a small bowl, whisk together the extra virgin olive oil, minced garlic, rosemary, thyme, sea salt, and black pepper.
Brush half of the herb oil mixture over both sides of the chicken breast, ensuring it is well coated.
Trim the woody ends off the asparagus spears and place them in a single layer on the other side of the baking sheet.
Drizzle the remaining herb oil over the asparagus and toss the spears with your hands to coat them evenly.
Thinly slice the half lemon into rounds and layer them over the chicken breast 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 ensure the juices remain locked inside.