Preheat the oven. Preheat the oven to 425°F. Line a rimmed baking sheet with parchment paper or foil for the vegetables.
Season the vegetables. Add the carrots, parsnips and beets to the baking sheet. Toss with olive oil, garlic, rosemary, thyme, salt and pepper. Spread into an even layer and roast for 15 minutes.
Prepare the glaze. While the vegetables roast, whisk together the fruit jam, red wine, garlic, rosemary, thyme, olive oil, salt and pepper in a bowl until well combined.
Prepare the pork. Pat the pork loin dry with paper towels and place it in a separate baking dish. Pour the jam glaze over the pork, turning it to coat all sides.
Roast the pork. Place the pork in the oven alongside the vegetables. Roast for about 15–20 minutes, depending on the thickness of the roast, checking the internal temperature after 15 minutes.
Check for doneness. Continue roasting until the thickest part of the pork reaches 145°F. If the glaze needs more caramelization, broil for 2–3 minutes, watching carefully so the sugars don't burn.
Rest and serve. Remove the pork from the oven and let it rest for at least 3 minutes before slicing. Check the vegetables for tenderness and continue roasting if needed. Slice the pork and serve with the roasted root vegetables, spooning any pan glaze over the meat.