Preheat your oven to 400°F (200°C).
In a small bowl, combine the minced garlic, sea salt, black pepper, and 0.25 tbsp of olive oil.
Rub the garlic mixture evenly over all sides of the pork loin roast.
Core the gala apple and cut into thick wedges, then roughly chop the yellow onion.
In a roasting pan, toss the apple wedges and chopped onion with the remaining 0.25 tbsp of olive oil, fresh rosemary, and fresh thyme.
Place the seasoned pork loin directly on top of the apple and onion mixture.
Roast in the center of the oven for 25 to 30 minutes, or until the pork reaches an internal temperature of 145°F.
Remove from the oven and let the roast rest for 10 minutes before slicing into medallions to ensure it remains juicy.