Preheat your oven to 400°F and line a large sheet pan with parchment paper for easy cleanup.
Halve the baby potatoes and snap off the woody ends of the asparagus spears.
Place the chicken breast, potatoes, and asparagus on the prepared baking sheet.
In a small bowl, whisk together the olive oil, minced garlic, rosemary, thyme, salt, and pepper.
Drizzle the herb mixture over everything on the pan, using your hands or tongs to ensure the chicken and vegetables are well coated.
Slice the lemon into thin rounds and layer them over the chicken and asparagus for a bright, citrusy infusion.
Roast for 20 to 25 minutes, or until the chicken reaches an internal temperature of 165°F and the potatoes are fork-tender.