Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper.
In a small bowl, whisk together the dried rosemary, thyme, garlic powder, sea salt, and black pepper.
Pat the pork tenderloin dry with a paper towel, then rub with half of the olive oil and the prepared herb seasoning until evenly coated.
Place the pork tenderloin on one side of the baking sheet and roast for 10 minutes.
While the pork is roasting, trim the woody ends off the asparagus and toss the spears with the remaining olive oil and minced garlic.
Remove the baking sheet from the oven, add the asparagus to the empty side, and return to the oven for another 12-15 minutes.
Check the pork with a meat thermometer; it is ready when it reaches an internal temperature of 145°F.
Transfer the pork to a cutting board and let it rest for 5 minutes before slicing into medallions and serving with the roasted asparagus.