To prepare a standing rib roast, trim the fat from the roast, leaving about a quarter inch layer of fat.
In a small bowl, mix thyme, salt, and pepper. Rub the mixture evenly all over the roast, pressing so that the herb mixture will adhere to the meat. Place the roast on a rack in a shallow roasting pan, fat side up.
Roast the beef at three-hundred-and-seventy-five degrees or until a thermometer inserted in the center of the narrow end reaches one-hundred-and-thirty-five degrees for medium (the wide end should be about 125° for rare), about 2 1/2 hours.
Transfer the roast to a platter, and let stand at least 10 minutes. The juices that accumulate on the platter will be added later to the sauce.
While the roast stands, defat the drippings by pouring them into a large liquid measuring cup lined with zip-top bag. Let it stand for a few minutes so the fat rises to top and the broth is on the bottom of the bag. Snip off one corner of the bag and squeeze the broth into the measuring cup. Discard the bag with the fat.
Add the juices that have accumulated from the standing roast to the pan, and stir. Add the defatted beef broth and brandy to the pan and stir, scraping up browned bits. Place the pan over high heat and stir until the mixture is boiling vigorously. Remove from the heat and pour the sauce through a fine strainer into a small bowl.
To carve the roast, transfer it to a cutting board placing the bone side down. Cut all the way down through the fat, following the line of the bone, until you reach the end of the bone. Slice the meat away from the bones in one chunk. You can save these bones and serve alongside the meat if you wish. Holding the roast with a carving fork, cut off the layer of fat—it will almost peel off. Then cut the meat into half-inch thick slices. Serve the meat with the sauce.