Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Pat the pork tenderloin dry with paper towels to ensure a good sear in the oven.
In a small bowl, combine the garlic powder, dried thyme, 0.25 tsp of sea salt, and the black pepper.
Rub the pork tenderloin with 0.5 tbsp of olive oil and the prepared herb seasoning mix.
Peel and dice the pumpkin into 1-inch cubes, then toss them in a bowl with the remaining 0.5 tbsp of olive oil, ground cinnamon, and the remaining salt.
Place the pork tenderloin in the center of the baking sheet and surround it with the pumpkin cubes in a single layer.
Roast for 20-25 minutes, or until the pork reaches an internal temperature of 145°F (63°C) and the pumpkin is fork-tender and caramelized.
Remove from the oven and let the pork rest for 5-10 minutes before slicing into medallions to serve alongside the pumpkin.