Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper.
Wash and peel the sweet potato, then cut it into 1-inch cubes. Trim the woody ends off the asparagus spears.
Mince the garlic cloves and finely chop the fresh rosemary and thyme leaves.
In a small bowl, combine half of the olive oil with the minced garlic, chopped herbs, sea salt, and black pepper to create a herb paste.
Pat the pork tenderloin dry with a paper towel and rub the herb paste evenly over all sides of the meat.
Place the pork tenderloin and cubed sweet potatoes on the prepared baking sheet. Drizzle the remaining olive oil over the sweet potatoes and toss to coat.
Roast in the oven for 15 minutes. Remove the pan briefly to add the asparagus spears to the remaining space on the sheet.
Continue roasting for another 10 to 15 minutes, or until the pork reaches an internal temperature of 145°F and the vegetables are tender.
Remove from the oven and let the pork rest for 5 minutes before slicing into medallions to serve alongside the roasted vegetables.