2 1/2 inch Porterhouse (need help)

Personally Medium Rare is way over done for such a fine peice of meet. As a punishment you should bring it to me so I can properly dispose of it.

Hot Tub it, Rub on some Salt and pepper (if you don't have a good steak rub) and sear it direct at 600.

Man, I'd like to see a few shots of that baby....before during and after the cook.

I'm thinking either the hot tub method, OR the reverse sear method. (This is where you cook it over a medium fire (or on a raised grate) until the internal is 100°, remove and rest 5 to 7 minutes while you ramp up the pit temp. Then finish over a hotter fire to within 5° of your personal doneness temp). On one that thick, no matter how you cook it, the turning frequency will be important for nice color and even doneness. (although the two methods will give you a good head start on even doneness).

It's a nickname (I believe came from AZRP) that refers to a method published in Cooks Illustrated in an article on how to improve the texture and flavor of grilled London broil. It involves seasoning the meat with salt (I use salt, pepper, and oftentimes cayenne), then sealing it in a zipper bag (I prefer a vacuum bag), then placed in a vessel of 100° tap water for 1 hour. This "hot tub" time does two things. First it allows the salt to mix with the juices and create a brine-like reaction. Second it raised the internal temperature of the beef to 70°+. By the way, food scientist Harold McGee mentiones heating a steak in warm water in his 1984 book On Food and Cooking.

The results are a flavorful piece of meat that will cook pretty fast because you are only taking it from 70° to 125°, instead of 40° to 125°. You don't to get too far from the cooker when you do this. The biggest advantage is the even doneness across the cross section of the steak. You won't get a rare center and medium rare edge.