Preheat your oven to 400°F and line a large sheet pan with parchment paper for easy cleanup.
Trim the woody ends off the asparagus spears and halve the baby potatoes.
In a small mixing bowl, whisk together the extra virgin olive oil, lemon juice, lemon zest, minced garlic, and chopped rosemary.
Place the chicken breast, halved potatoes, and asparagus onto the prepared sheet pan.
Drizzle the lemon-herb mixture over the chicken and vegetables, then sprinkle evenly with sea salt and black pepper.
Toss the vegetables with your hands or tongs to coat them thoroughly, and ensure the chicken is well-covered in the marinade.
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 potatoes are golden and tender.
Remove from the oven and let the chicken rest for 5 minutes before slicing to ensure it stays juicy.