Herbed Roast Beast with salt crust

My Good Idea was to combine two recipes from Gourmet Magazine (1991) and epicurious.com.
I've made this every Christmas since 2004.

Ingredients:

Prime rib roast (also called standing rib roast), 4 ribs in size.  If you need more for a large group, get two separate roasts.  I once tried one big honkin' one and it took forever to cook in my home oven.  And if you're making two, double the herb rub below.

Herb rub

• 1 tbsp whole black peppercorns
• 2 bay leaves
• 1 tsp kosher salt
• 1 tbsp minced garlic
• 1 tsp chopped fresh thyme
• 1 tsp chopped fresh rosemary
• 1 tbsp olive oil
• Giant zip lock plastic bags in which to refrigerate the roast

Salt crust

1 box kosher salt (saw that one coming, didn't ya?)

Aye, there's the rub

Grind peppercorns and bay leaves with salt to a powder in a coffee grinder.
Transfer to a bowl (I don't have a mortar & pestle, but if you do, go to town) and add garlic, thyme, and rosemary.  Make a smooth paste.
Stir in olive oil.
Rub paste all over roast.
Zip the beast into the zip lock bag and refrigerate at least overnight.

When ready to roast, let stand at room temperature for an hour or two.

Ready to Roast

Preheat oven to 325 degrees.
In a bowl, gradually add water to 3 cups of salt until it forms a stiff paste resembling wet snow.  Put the roast on a rack in a roasting pan, fat side up.  Cover the top with a layer of salt mixture about 1/4 inch thick.  Cook for 2 hours without opening the oven door, then check the temperature.  It's ready to come out at about 145 degrees, and will be mostly medium.  Dead center will be the rarest part.

Remove from pan and let it set on a platter for 25 minutes while you make au jus.  (Don't forget to fish any chunks of salt out of the pan before you make it.)  Then pry off the salt crust and discard.  But get out your camera phone first; it looks pretty weird. 

Oh, and don't forget to make stock from the leftover ribs.  It will make the best vegetable beef soup.