Years ago I read a recipe in Southern Living Magazine entitled "The Perfect Prime Rib" and it was done by seasoning the prime rib with whatever spices you desire. Put down a bed of rock salt and put the prime rib on top. Encase it in about an inch or so of rock salt and sprinkle it with water and then bake at 500*. The salt will be so hard you have to bust it loose with a hammer...or the hard head of a teenager. As far as how long to cook it, I would put a thermometer probe in it before wetting down the salt. Dee