First you will need a Prime Rib roast. How big should it be? Depends on how many people and how much meat they like to eat! And how much you want to spend!
The rule of thumb is: 1 Rib feeds 2 People. So a 2 Rib roast would feed 4 People. For a backyard BBQ feast that has a lot of other food you can probably estimate 1 Rib for 2.5 People. This is assuming 1 Rib is equal to about 1 Kilogram or about 2.2 Pounds.
Adjust things accordingly for weight!
When you buy your Prime Rib roast look for one with good layer of fat. Fat is flavour. Fat keeps the meat moist while cooking. You can always cut off the fat when serving! You want at least a 1/4 inch (less than 1 cm) of fat on the side away from the bones.
Get a GOOD Meat Thermometer!
The most important item you need in cooking a Prime Rib roast is a good meat thermometer! Prime Rib should not be overcooked. Yes you can estimate times but really the best way to cook this premium cut of meat is with a good, reliable and accurate thermometer. I use a digital thermometer that stays in the roast throughout the cooking process. The one I use has a long lead from the meat probe to an exterior display that sits outside the oven. Very nice for monitoring the cooking progress without opening the door!
COOKING THE ROAST
1) Let the meat come to room temperature before roasting. This may take an hour. A cold Prime Rib will not cook properly, with the outer portion overcooking. Never try and cook a frozen Prime Rib roast!!! Use paper-towels to pat dry the surface of the meat.
2) DO NOT SALT. Salt pulls the moisture from the meat. Season with garlic, or some other rub if you desire. I just rub on some fresh ground pepper.
3) OPTIONAL: Garlic! grab a garlic clove or two and slice into small slivers. Now take a very sharp thin knife and slice small holes all around the roast, inserting a garlic sliver into each hole.
4) OPTIONAL: While the roast is sitting out (see step 1) you can do this! BBQ Rib is even better with a good roast rub. Here is a rub recipe (and you can make your own!).
1 tablespoon coarse ground black pepper
1 teaspoon dried minced onion
1 teaspoon dried minced garlic
1/2 teaspoon dried parsley
1/2 teaspoon red pepper flake
Mix together the pepper, onion, garlic, parsley and pepper flakes.
Remove the butcher’s twine and lightly coat the roast and ribs with oil.
Season on all sides (including the space between the ribs and roast) with the dry rub. Re-tie the beef roast and ribs back together. Now let sit at room temperature for an hour.
5) Set up your BBQ (grill) for indirect heat and preheat to low (250-300°F).
6) Place the roast, bone-side down, on a roasting rack and pan combination. Add enough beef stock or water to fill the pan about 1 inch deep. Optional: Add some dried mushrooms to flavor the liquid base! If you are using a digital thermometer insert it into the roast!
7) Place the roast and pan on the grill on the indirect side where you don’t have any burners on. Close the grill lid and cook until the rib roast hits 10 °F less than your desired level of doneness.
NOTE: This should take about 3 hours for medium rare. It’s a good idea to turn the roast around every 45 minutes or so. (For rare – pull at internal temperature of 115°F. For medium rare – 125°F. For medium – 135°F).
8) Remove the roast and pan set up and let rest at room temperature until the internal temperature stops rising – about 20 minutes. Meanwhile, turn up the grill heat to high (you want it very hot – about 500 °F).
9) Taste the au jus (seasoned broth in the pan) and season to taste with salt and pepper to taste. Keep the au jus warm.
10) Now fully remove the rib bones. Then place the rib bones cut side down over the heat. Also sear the roast 2-3 minutes on the cut side and 1-2 minutes on the other sides.
11) Once the outside of each portion is nicely seared remove from the grill. You may let it rest for a few minutes but it isn’t needed – as it already settled during the previous rest.
12) Slice as desired. Top with some of the au jus and serve.
Sit back and enjoy summer!