Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper.
In a small bowl, whisk together the olive oil, lemon juice, lemon zest, minced garlic, dried oregano, sea salt, and black pepper to create the marinade.
Place the chicken breast, halved baby potatoes, and trimmed asparagus spears on the prepared sheet pan.
Drizzle the lemon-herb marinade over the chicken and vegetables, tossing well to ensure everything is evenly coated.
Spread the ingredients into a single layer, ensuring the chicken has space to roast properly and the vegetables aren't crowded.
Bake for 20-25 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 to keep it juicy.