I do not speak French. This is not something I'm proud of, as I could have, and should have, picked it up by now. With that said, the mispronunciation of French culinary terms is one of my great guilty pleasures.
I know it's "oh" jus, and not "ahhh" jus, but that's how I grew up saying it, and I don't have any plans to start saying it right at this advanced age. Besides, the proper pronunciation sounds like you are surprised you're getting a sauce, and my way sounds like you are happy about it.
This is the most minimalist method for doing a quick au jus for your prime rib of beef. In a restaurant that specializes in prime rib, they have the benefit of massive amounts of bones and scraps to make a reduced, rich jus without having to thicken it.
At home however, we need to cheat a little bit. You can do this without the flour step, but I think most people prefer this beefy dipping sauce to have a little body to it. Not thick like gravy, but just a little something to help it adhere to the meat. By the way, that thin film of beef fat floating on the surface is fully intentional, as you are about to hear. Enjoy!
Beef Au Jus Ingredients:
1/4 cup beef fat, plus pan drippings from a cooked prime rib or other roast beef
1 1/2 tablespoon white flour
2 cups rich beef broth
salt and fresh ground black pepper to taste
*makes about 1 1/2 cups depending on how much you reduce