Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper.
Halve the baby potatoes and trim the tough, woody ends off the asparagus spears.
In a small mixing bowl, whisk together the olive oil, lemon juice, lemon zest, rosemary, garlic powder, salt, and pepper.
Place the chicken breast, potatoes, and asparagus onto the prepared baking sheet in a single layer.
Drizzle the lemon-herb dressing over the chicken and vegetables, tossing the produce to coat and ensuring the chicken is well-covered.
Roast in the center of the oven 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.