Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper.
Scrub the sweet potato and carrots, then dice the potato into 1/2-inch cubes and slice the carrots into thin rounds.
Place the chicken breast, sweet potato cubes, and carrot rounds onto the prepared baking sheet.
Drizzle the olive oil and lemon juice over the chicken and vegetables, then sprinkle evenly with oregano, garlic powder, sea salt, and black pepper.
Toss the vegetables to coat and flip the chicken to ensure it is seasoned thoroughly on both sides.
Roast in the oven for 15 minutes.
Remove the tray from the oven, add the asparagus spears to the empty spaces, and toss them lightly in the pan juices.
Return the tray to the oven and roast for an additional 10 to 12 minutes until the chicken reaches an internal temperature of 165°F and the vegetables are golden and tender.