1. Dry the beef with paper towels while you preheat the oven to 460F. Then, rearrange the shelf so the roast will be positioned at the center of the oven.
2. Arrange the quartered onions, garlic, and herb sprigs in a roasting pan. Then, combine the ingredients for the herb butter and slather a thin layer under the standing rib. Place this side on the herbed pan and spread two-thirds of the butter mix on the beef surface and sides.
3. Roast the standing rib for 20 minutes, then remove and apply the remaining butter over the surface. Then return to the oven, reduce the temperature to 250F, and roast again for an hour and a half. Ensure to baste the roast with the pan juices every 30 minutes.
4. Cook until the internal temperature reaches 118F. Then, transfer the roast to a serving plate and tent loosely for 20 minutes to rest, so the carryover cooking pushes it to 125F. Slice the standing rib roast and serve with your favorite sauce. You can make such with the tasty pan juices left.

You can also see this video for more ideas about how long to cook a standing rib roast.