Place the roast in a shallow baking dish and rub with the salt and pepper. Place in the refrigerator uncovered 8 hours or overnight. Before cooking, let the roast sit at room temperature for about 1 hour. Using a thin sharp knife, poke slits all over the top and sides of the roast and stuff each slit with a garlic sliver.
Preheat the oven to 400 degrees F.
In a medium roasting pan fitted with a rack, place the beef on the rack and pour 1 cup water, 1/4 cup broth, and 1/2 cup wine into the bottom of the pan. Roast the beef for 15 minutes and turn down the heat to 325 degrees F. Cook for an additional 45 minutes to an hour, until the internal temperature of the beef is 120 degrees F, adding the remaining 1/4 cup water to the pan, if necessary.
Remove the roast from the oven, transfer the roast to a warmed platter and tent with foil to rest. Meanwhile, place the roasting pan over high heat and deglaze with the remaining wine. Add a large sprig of fresh rosemary to the sauce. Reduce by 1/3. Stir the flour into the remaining 3/4 cup broth and then whisk into the sauce. Simmer until thickened. Remove the rosemary sprig, stir in the butter and season with salt and pepper, to taste. Serve the sauce with the sliced roast beef.