Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper.
Halve the baby potatoes and place them on one side of the baking sheet.
Drizzle the potatoes with half of the olive oil and sprinkle with a pinch of the sea salt and black pepper.
Roast the potatoes in the oven for 15 minutes to give them a head start.
While the potatoes roast, whisk together the remaining olive oil, lemon juice, lemon zest, minced garlic, and dried oregano in a small bowl.
Remove the baking sheet from the oven and place the chicken breast in the center, then arrange the trimmed asparagus spears on the remaining open space.
Brush the lemon-herb mixture generously over both the chicken breast and the asparagus spears.
Season the entire pan with the remaining sea salt and black pepper.
Return the pan to the oven and roast for an additional 15 to 20 minutes, or until the chicken reaches an internal temperature of 165°F and the asparagus is tender and slightly charred.
Let the chicken rest for 5 minutes before slicing to ensure it stays juicy.