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.
In a small mixing bowl, whisk together the extra virgin olive oil, lemon juice, dried oregano, garlic powder, sea salt, and black pepper until well combined.
Place the chicken breast, halved potatoes, and trimmed asparagus onto the prepared sheet pan.
Drizzle the lemon-herb mixture over the chicken and vegetables, using your hands or tongs to toss everything until evenly coated.
Spread the ingredients into a single layer, ensuring the chicken is in the center and not covered by vegetables.
Roast in the oven for 20 to 25 minutes, or until the chicken reaches an internal temperature of 165°F and the potatoes are fork-tender.
Remove from the oven and let the chicken rest for 5 minutes before slicing it into strips.
Garnish the entire dish with finely chopped fresh parsley and serve immediately.