Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Peel the sweet potato and cut it into 1/2-inch cubes. Place them on one side of the baking sheet.
Drizzle the sweet potatoes with 0.5 tbsp of olive oil and a pinch of the sea salt and black pepper, tossing to coat evenly.
Roast the sweet potatoes for 10 minutes while you prepare the chicken.
In a small bowl, whisk together the remaining 0.5 tbsp of olive oil, lemon juice, dried oregano, dried thyme, garlic powder, and the remaining salt and pepper.
Pat the chicken breast dry with a paper towel and brush the herb mixture over both sides of the meat.
Remove the baking sheet from the oven. Move the potatoes to one side, place the chicken in the center, and add the asparagus spears to the remaining space.
Return the sheet to the oven and roast for 15 to 20 minutes, or until the chicken reaches an internal temperature of 165°F and the potatoes are fork-tender.
Let the chicken rest for 5 minutes before slicing to ensure the juices stay locked inside.