Preheat your oven to 400°F (200°C) and line a large rimmed sheet pan with parchment paper for easy cleanup.
Wash and halve the baby potatoes, and trim the tough, woody ends off the asparagus spears.
Place the chicken breast, halved potatoes, and trimmed asparagus in a single layer on the prepared sheet pan.
In a small glass jar or bowl, whisk together the extra virgin olive oil, lemon juice, lemon zest, minced rosemary, garlic powder, sea salt, and black pepper.
Drizzle the lemon-herb mixture over the chicken and vegetables, using your hands or tongs to toss everything until thoroughly and evenly coated.
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 fork-tender.
Remove from the oven and let the chicken rest for 5 minutes before slicing to ensure the juices redistribute for a moist result.
Plate the sliced chicken alongside the roasted potatoes and asparagus, drizzling any remaining pan juices over the top before serving.