Preheat your oven to 400°F and line a large sheet pan with parchment paper for easy cleanup.
Peel the sweet potato and dice it into small 1/2-inch cubes to ensure they cook at the same rate as the chicken.
Trim the woody ends off the asparagus spears and set them aside.
Place the chicken breast, sweet potato cubes, and asparagus on the prepared sheet pan.
Drizzle the olive oil and lemon juice over the chicken and vegetables.
Evenly sprinkle the dried oregano, garlic powder, sea salt, black pepper, and fresh lemon zest over everything.
Toss the vegetables with your hands or tongs to coat them thoroughly in the oil and seasonings.
Roast in the center of the oven for 20 to 25 minutes, or until the chicken reaches an internal temperature of 165°F and the sweet potatoes are tender.
Remove from the oven and let the chicken rest for 5 minutes before slicing to ensure it remains juicy and tender.