Important: Before beginning this recipe, please read my web page on purchasing, preparing, and cooking perfect Classic Prime Rib.
Preheat oven to 350 degrees F. Let roast stand at room temperature for 1 hour.
In a small saucepan over medium-high heat, boil balsamic vinegar until it reduces to 1/4 cup, approximately 3 minutes. Remove from heat and set aside.
Finely mince the parsley. Mix together with the minced garlic, 1/4 teaspoon salt, and a generous amount of pepper. Using the tip of a sharp knife, bore 7 to 10 narrow holes, each about 1 1/2" deep, in the rib roast. Fill the holes with the parsley-garlic mixture. Spread any remaining mixture over the surface of the roast. Sprinkle all sides of the meat with salt and pepper.
Place the roast, ribs down in a roasting pan. Roast for 15 minutes. Reduce oven temperature to 325 degrees F. and continue to roast an additional 2 to 2 1/2 hours or until the internal temperature reaches desired temperature on a meat thermometer (see below).
Rare - 120 degrees F.
Medium Rare - 125 degrees F.
Medium - 130 degrees F.
What constitutes rare and medium-rare cooked meat? To satisfy government home economists, the Beef Council says rare beef means an internal temperature of 140 degrees F. Well, that is ok if you like well-done and dry meat. If you like moist, rosy meat (like I do), rare begins when the internal temperature registers 120 degrees F. and starts to become medium rare at 125 or 130 degrees F. To cook your meat properly, you must purchase and use a good instant-read digital >meat thermometer.
This is the type of cooking and meat thermometer that I prefer and use in my cooking. I get many readers asking what cooking/meat thermometer that I prefer and use in my cooking and baking. I, personally, use the Thermapen Thermometer shown in the photo on the right.
Remove from oven and transfer onto a cutting board; let stand 15 minutes before carving (the internal temperature will rise 5 to 10 degrees after it is removed from the oven).
Pour off all but 2 teaspoons fat in the roasting pan. The pan juices should be few but concentrated and caramelized. Place the roasting pan over two (2) burners on high heat. Add the water, scraping up all the browned bits on the bottom of the pan and stirring until they are incorporated. Boil the liquid until it reduces to 3/4 cup, approximately 3 to 4 minutes.
Stir in enough of the balsamic glaze to create a tart edge in the flavor of the juices, approximately 1 to 2 tablespoons. (Reserve any extra glaze for another use.) Add the Worcestershire to the sauce; remove from heat and keep warm.
After slicing the roast, add any accumulated meat juices to the balsamic sauce. Serve the meat slices on warmed plates with balsamic sauce on the side.
Makes 6 to 8 servings.