Rin Roast with Alton Brown Method.

Keep experimenting with your tagine. I have used one for about 20 years and have yet to have a failure. However, I stick
to Moroccan stews and the like - have not tried a whole hunk of meat. I'll give it a try.
Also, I have always used my tagine on the stove top and control the temp to be a simmer for the liquids I use and "stew" for about 3 hours. (gas stove) I am an advocate for either cooking at 225F or 500F. 350F is for Betty Crocker fans.

Yum -- sounds fantastic. Thanks for the update! My family made Waverly's Prime Rib from the site and we didn't get much jus either (for the same reason), but no one was complaining.

Here's the Follow up:
Using the low then high temp tech worked perfectly. The tagine I used wasn't quite large enough for a rack, So I sliced potatoes on onions in half and rested the beef on that. 4 hours later it was 118 internal. The potatoes where still raw. I removed and tented the beef on another shallow pan with a rack and put the potatoes and other veggies back in the oven at 500 for about 30 mins.
Then the prime rib when in the high heat blast for 10 mins to crust up. and ended with perfect rare inside with med-rare endcap.

Surprisingly there very little Juice to salvaged to make Au Jus...practically none at all. mostly it was fat. But I served it with horseraddish/sourcream/mayo/lemon sauce and all was good.
The special hardware with the high dome of the tagine or the flowerpot thingy Alton Brown mentions might be critical to this method as I think it helps keep moisture in...the big suprise was that I barely any juice--which might be a good thing as it was VERY tender and moist; and this was a 'choice' cut of 'prime' rib.

I see. I think this is very promising -- I'd just keep an eye on them along the way and poke/taste as you go, but I think you're onto something.

Hi Sam, what a cool method. I think the carrots and potatoes would be delicious slow-roasted (sort of like cooking them in the Crock-pot, without the liquid), although I don't think they'd need as much time as the roast. So I'd throw them in midway through. Same deal with the heat blast -- you might want to give them a little blast, but keep an eye on them and pull them out before the rib roast if they're starting to get crispy. Please report back!

and I messed up the link to the alton brown thing. Here you go.
http://www.foodnetwork.com/recipes/alton-brown/dry-aged-standing-rib-roast-with-sage-jus-recipe/index.html

well, that posted before I had a chance to review. Okay, here's the method. http://food52.com/hotline/23230-rin-roast-with-alton-brown-method
Basically, a very low temp slow roast..almost a bit scary at that low a temp. I'll be using a large Emile Henry Tagine which has a high top and a put in a small round wire rack for the roast. (of course preheating the clay tagine). The problem is when to put in the red potatoes, and carrots so they get roasted too...it's only 200-250 for the first few hours then just a blast of 500 to finish the roast. Would the potatoes be okay at a low/slow temp then a heat blast?