Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper for easy cleanup.
Pat the chicken breast dry with a paper towel to ensure a golden sear, then place it on one side of the prepared baking sheet.
In a small bowl, whisk together the olive oil, minced garlic, chopped rosemary, and thyme.
Brush half of the herb oil mixture over the chicken breast and season with half of the sea salt and black pepper.
Trim the woody ends off the asparagus and place the spears on the other side of the baking sheet.
Drizzle the remaining herb oil over the asparagus, tossing gently to coat, and season with the remaining salt and pepper.
Place thin slices of the lemon over the chicken and asparagus to infuse them with bright citrus notes.
Roast for 20-25 minutes, or until the chicken reaches an internal temperature of 165°F and the asparagus is tender and slightly charred.
Rest the chicken for 5 minutes before slicing to keep it juicy, then serve immediately.