Get a nice 5# prime rib; if larger adjust times. I prefer Angus and bones in but I buy what's on sale. I got this Angus one for $7.27/# and was happy. Spice it up. Be creative from your spice cabinet and don't spare the spice. If you're at a loss what to do here do your first one with garlic powder, paprika, pepper or tarragon pepper or Mrs. Dash. Pat the spices in, triple wrap in plastic and fridge for 24 hours if you have the time. Put 3/4" of rock salt (I buy it by the 50# bag; its really cheap; get food grade) in the bottom of the dutch oven. Lay the roast in, fat up. Continue to fill dutch oven with rock salt, pushing the roast away from contact with cast iron. When its full, cover and put into oven preheated to 350F while at the same time lower the oven temp to 225F. Leave it alone for 3 hours. Test it with an internal instant thermometer; you're looking for about 140 for Medium Rare. Don't pull it until you have that. Let Dutch Oven sit out for 30 minutes. Pull the roast from the salt, scrape the salt off and serve. You'll be surprised that its not all salty; just juicy/flavorful/wonderful.