In a small bowl mix together the garlic, onion, paprika, salt, and pepper.
Add the pork and potatoes to a large mixing bowl, drizzle with the oil and flip the pork and potatoes around to coat in the oil. Sprinkle the spice mix over the pork and potatoes and flip around again to coat in the spices.
Lay the pork in the center of a rimmed baking sheet and lay the potatoes in a single layer on the sides of the pork.
Place the baking sheet in the preheated oven about 30 minutes or until the pork is cooked (an internal temperature of about 140°F) and the potatoes are tender on the inside.
Take out of the oven and allow the pork to rest for 10 minutes before slicing.