1. Bring Roast to Room Temperature: Remove roast from the refrigerator and let sit for 1 hour to ensure even cooking.
2. Prepare the Roast: Pat the meat dry with paper towels. In a small bowl, combine olive oil, rosemary, thyme, salt, and pepper. Rub mixture all over the roast.
3. Roast the Beef: Preheat the oven to 500°F. Place roast on a wire rack in a roasting pan or directly on a foil-lined sheet pan. Roast 15 minutes to brown the exterior. Reduce oven temperature to 300°F and continue roasting 25–45 minutes, or until an instant-read thermometer inserted into the side of the roast reads 130–135°F for medium-rare. Start checking at 25 minutes.
4. Air Fry the Potatoes (while beef roasts): When the roast has about 20 minutes left, preheat the air fryer to 400°F. In a large bowl, toss potatoes with olive oil, rosemary, parsley, thyme, salt, pepper, and red pepper flakes. Arrange in a single layer in the basket (cook in batches if needed). Air fry 12–15 minutes, shaking halfway through, until golden and tender. Keep warm, loosely covered with foil.
5. Rest the Roast: Remove roast from oven and tent loosely with foil; let rest for 20 minutes before slicing. If potatoes need reheating, pop them back in the air fryer or oven at 400°F for 3–5 minutes.
6. Serve: Slice roast to desired thickness. Spoon pan drippings over meat and serve with crispy air-fried potatoes. Garnish with extra parsley if desired.