Preheat your oven to 400°F (200°C).
Halve the baby potatoes and trim the tough, woody ends from the asparagus spears.
In a small bowl, whisk together the olive oil, lemon juice, lemon zest, minced garlic, dried oregano, sea salt, and black pepper.
Place the chicken breast and halved baby potatoes on a sheet pan lined with parchment paper.
Brush the chicken and potatoes with approximately half of the lemon-herb oil mixture, ensuring they are evenly coated.
Roast in the center of the oven for 15 minutes.
Remove the pan from the oven, add the asparagus spears, and drizzle with the remaining lemon-herb sauce.
Return the pan to the oven and roast for an additional 10 to 12 minutes until the chicken reaches an internal temperature of 165°F and the potatoes are fork-tender.