Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper.
Dice the sweet potato into half-inch cubes and trim the tough, woody ends off the asparagus spears.
In a small mixing bowl, whisk together the olive oil, lemon juice, lemon zest, dried oregano, garlic powder, sea salt, and black pepper.
Place the chicken breast, sweet potato cubes, and asparagus on the prepared baking sheet in a single layer.
Drizzle the lemon-herb mixture over the chicken and vegetables, tossing them gently to ensure every piece is thoroughly and evenly coated.
Roast for 20 to 25 minutes, or until the chicken reaches an internal temperature of 165°F and the sweet potatoes are fork-tender and slightly browned.
Remove from the oven and allow the chicken to rest for 5 minutes before slicing to ensure the juices remain locked inside.