Preheat your oven to 400°F (200°C) and line a large rimmed sheet pan with parchment paper for easy cleanup.
Prepare the vegetables by halving the baby potatoes and trimming the tough, woody ends off the asparagus spears.
Place the chicken breast, halved potatoes, and trimmed asparagus onto the prepared sheet pan in a single layer.
In a small glass jar or bowl, whisk together the extra virgin olive oil, fresh lemon juice, lemon zest, dried oregano, garlic powder, sea salt, and black pepper.
Drizzle the lemon-herb marinade 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 fork-tender and golden.
Remove from the oven and allow the chicken to rest for 5 minutes before slicing to ensure the juices redistribute for maximum tenderness.