Step 1

HEAT WATER IN SOUS VIDE MACHINE/OVEN: Fill the sous vide container about 3/4 full with water. Set the temperature to 132-134F for medium rare or according to your manufacturer's temperature suggestions. For medium cook, set to 140F/60C. The water will take about 15 minutes to reach the correct temperature (or less if you start with warm water).

Step 2

SEASON MEAT: Brush with oil. Generously sprinkle the roast with kosher salt, pepper, thyme, rosemary and garlic powder on all sides.

Step 3

PREPARE MEAT FOR SOUS VIDE: If using a vacuum seal, fold over a flap on one 1-quart vacuum seal bag. Place meat inside the bag and unfold the flap. Plug in the vacuum sealer machine. Seal the bag (and vacuum out the air) as per machine instructions. (Note 1 for displacement method with ziploc).

Step 4

SOUS VIDE MEAT: Plunge the bag into the pre-heated water bath. It will sink to the bottom. Cover the sous vide container. Walk away. Remove the bag of meat in 3 1/2 hours (or maximum 6 hours). If meat is lesser quality, sous vide for 4 - 4 1/2 hours. Note 2

Step 5

SEAR OUTSIDE OF BEEF TO FINISH ROAST: Remove meat from sealed bag, reserving the juices accumulated in the bag for gravy if desired. Pat dry well with paper towels. Rub oil over meat and sprinkle again lightly with kosher salt. Let it sit for 10 minutes while you prepare your skillet (cast iron is best but any skillet will do). Heat skillet to high (8/with a teaspoon of oil. Sear beef about 1 minute on each side (and the top) to achieve a deep brown color. Remove from skillet and keep warm while you prepare a quick gravy if desired, adding the reserved juices from the bag used to sous vide the prime rib. Slice the beef and serve with horseradish, horseradish cream or gravy. Sprinkle lightly with finishing sea salt if desired.