Preheat the oven to 400°F. Line a 13 x 9 x 2-inch roasting pan with foil. In a small bowl, mix together to the garlic, rosemary, salt, and pepper. Using your fingers, rub the mixture all over the pork.
Place the pork, fat side down, in the roasting pan. Roast for 30 minutes, turn over and roast for another 20-30 minutes or until pork registers at 155°F. Remove from the oven and let stand for 10 minutes. While pork rests, pour any leftover pan juices into a small bowl or gravy boat.
After flipping the roast over, peel and spiralize the sweet potato (Blade C or D), onion (Blade A), and parsnip (Blade D). Lay the veggies out on a parchment paper lined baking sheet and drizzle with the oil. Season with thyme, salt and pepper and toss to combine. Roast for 15 minutes or until vegetables soften.
When pork has rested, slice crosswise into 1/3” thick slices. Arrange the slices on a platter and serve alongside the spiralized veggies.