Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper for easy cleanup.
In a small mixing bowl, whisk together the olive oil, lemon juice, minced garlic, dried oregano, dried thyme, sea salt, and black pepper to create the marinade.
Peel and dice the sweet potato into 1-inch cubes and trim the woody ends off the asparagus spears.
Place the chicken breast on one side of the baking sheet and arrange the sweet potato cubes and asparagus on the other side.
Drizzle the lemon-herb marinade over the chicken and vegetables, using a brush or your hands to ensure everything is evenly and thoroughly coated.
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 and golden.
Remove from the oven and let the chicken rest for 5 minutes before slicing to keep the meat succulent and juicy.