A diffucult process that results in fairly ok beef for beef on weck:
Find a butcher who will sell you prime rib with additional au jus, and will let you bring back the cooked meat so he can slice it.
Rub the meat with salt, pepper, and garlic, and put it in a pan with the bone on the bottom. Roast at 425 degrees for 20 - 25 minutes, and then cook an additional 16 minutes per pound at 325 degrees.
This cut of meat will not produce a lot of juice in the pan, which is why you need the additional au jus from the butcher. I would start with one cup of jus, and add one half cup for every serving.
Bring the cooked beef back to the butcher, and have him slice it as thin as possible. You can slice it yourself if you feel up to the challenge. I really do think it’s easier to drive all the back to the butcher rather than get frustrated that I can’t cut uniformly paper thin pieces of beef.
Add any drippings from the pan to the jus, and heat in a crock pot. Place the beef next to the crock pot on a buffet, and have your guests “flash” their serving of beef in the jus by putting it in the crock pot for 3 or 4 minutes. If you think everyone will serve themselves very quickly, you can put the meat right in the pot, but if you leave it in there more than ten minutes it will get overcooked and tough.
This is not very helpul if you are looking to make only one or two sandwiches. It is best if you serve it the same day that you roast the meat, or at the very most, one day after.
I shouldn’t have said this was difficult, it’s actually quite easy, the real problem is that it is annoying because (a) prime rib is expensive, (b) you have to make two trips to the butcher, © it’s hard to make a small portion, and (d) you have to find the kimmelweck rolls. When I’m in NYC, I serve them on regular kaiser rolls.
Aside to Elmwood … I noticed in another thread that you live in Colorado now … by any chance, are you the guy who used to have the website about lawn ornaments in Cheektowaga and other Buffalo customs?