Prime Rib Roast with Cracked Pepper on the Grill

For my Mother's Birthday my Dad and I decided that we would cook a boneless prime rib roast on the grill. We picked one up at the grocery store that weighed in at about 10 lbs. It was well marbled and had a nice fat cap on it, not too thick. It was tied up into a compact shape.

INGREDIENTS
    5-10 llb Boneless Prime Rib Roast
    1/4 c. Black Whole Peppercorns
    1/8 c. White Whole Peppercorns
    3 Tbs. Whole Mustard Seeds
    Kosher Salt

DIRECTIONS

1. Roast the peppercorns and mustard seeds in a saute pan over medium low heat until the spices are toasted but not burned. Keep them moving in the pan by shaking it or using a spatula. If you burn them, discard and start again
2. Pour the spices out onto a paper plate or smooth dish cloth over a solid and sturdy cutting board and allow them to cool a bit. Cover the spices with another plate or towel and smash them with a smooth headed hammer or heavy pan. You want to crack the peppercorns and mustard seeds, but not completely turn them into dust
3. Do the next step over a large roasting pan so the spices do not get all over the place and you can roll the meat in the spices left in the bottom of the pan.
4. Dry off the meat and then liberally sprinkle kosher salt all over it. Do not be shy with the salt, it will help draw protein rich moisture to the surface that promotes browning.
5. Take your smashed up spices and press into the meat on all sides. Do not forget the ends. Make sure that the whole roast is covered by the spices.
6. Let the roast sit for 15 minutes with the spices on it. If you have to wait more than 15 minutes before cooking, place the roast back in the fridge and remove it 15 minutes before you plan to put it on the fire. This lets the meat warm up a little before the cooking process, allowing it to be done in less time. Less time means that less moisture is lost during the cooking process.
7. Prepare an indirect fire in your grill and adjust the temperature to between 350 and 375 °F. If you only have an oven, use that (set at the same temperature). Place the meat in the cooker and use a pan to collect the fat that cooks off.
8. Roast until the meat reaches an internal temperature of 130 °F, about 12-15 minutes per pound, but USE A THERMOMETER. A remote thermometer works very well in this case, but if you want the best get a Thermapen from ThermoWorks. 
9. Remove from cooker or oven and place on a cutting board to rest for at least 15 minutes. If you have to hold it longer than the resting period, cover it with foil and then a clean thick dish towel to keep it warm.
10. Slice it into 1/4 inch thick slices and serve with an Au Jus, delicious!

Pair it with my Scalloped Potatoes for an awesome Meat and Potatoes Feast.