Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Wash the sweet potato and dice it into 1-inch cubes, then trim the woody ends off the asparagus spears.
Mince the garlic cloves finely.
In a mixing bowl, toss the sweet potato cubes with 0.5 tbsp of olive oil and a small pinch of the sea salt and black pepper.
Spread the sweet potatoes onto the prepared baking sheet and roast for 10 minutes.
While the potatoes are roasting, rub the chicken breast with the remaining 0.5 tbsp of olive oil, minced garlic, dried rosemary, dried thyme, and the remaining salt and pepper.
Remove the baking sheet from the oven, move the potatoes to one side, and place the chicken breast and asparagus on the other side.
Return the tray to the oven and roast for an additional 15 to 20 minutes, or until the chicken reaches an internal temperature of 165°F.
Remove from the oven and let the chicken rest for 5 minutes before slicing to ensure it stays juicy and tender.