Process

How to Roast a Prime Rib to Medium Rare (140 degrees internal temperature)
While roasting is the simplest method know to man, it is also the most complicated and controversial.

Let the Prime Rib sit on the counter for an hour until it gets to room temperature.
70-degrees internal temperature.

Rub the prime rib generously with soy sauce
Season liberally with kosher salt and pepper.
I use Food Guru Steak Spice, it makes everything taste Great!
Transfer the prime rib to a clean roasting pan with a rack.
*We don't want any excess soy sauce in the pan because it will burn.
Stand it Up.
Add two onion halves and two carrots.
Pour 1 quart of water in the bottom of the pan

Pre-Heat the oven to 425-degree with NO fan or blower.
Roast meat for 20-minutes. This will create a great crust.

Drop the temp down to 250 degrees for 30 minutes.

Finish by dropping the temperature to 140 degrees for one hour.
If your oven doesn't go down to 140-degrees, go to your lowest setting for 30-minutes
Then turn the oven OFF and allow the risidual heat to stay in the oven
Allow Beef to rest at this temp for one hour.
The Internal temperature should be exactly 140-degrees.

DO NOT open the oven door during this process or you will lose the risidual heat and the timing will be completely off.

Do Not try to cook other items in the oven with the Prime Rib.
If your oven doesn't go down to 140-degrees, go to your lowest setting for 30-minutes
Then turn the oven OFF and allow the prime rib to sit for another 30-minutes

Internal Temperature
Rare = 130 degrees F
Medium Rare = 140 degrees F
Medium = 150 degrees F
Medium Well = 160 degrees F
Well Done = 180 +

NOTE:
One important variable in the roasting process is the temperature of the meat WHEN it goes in the oven.
If you take the roast straight from the fridge, it will be 40 degrees.
If you let it warm up to room temperature, it will be 70 degrees when it goes in the oven.
These 30 degrees could be the difference between rare and medium well meat.
Let the meat come to room temperature BEFORE putting it in the oven.