Roasted Prime Rib dinner is a great Saturday or Sunday family dinner. This is a paleo recipe and of course Italian! Enjoy
Preheat oven to 425 degrees F
For the beef: Allow the beef to stand at room temperature before roasting, 30 minutes. Place your oven rack in the center of the oven.
In a small bowl combine rosemary, salt, pepper and garlic. Make 1-inch-long, 1/2-inch-deep slits all over the meat using a paring knife. Rub the garlic mixture into the slits and onto the rest of the meat. Place the meat, fat-side up, in a shallow roasting pan. Roast for 45 minutes. Cover the meat with foil and continue to roast until a meat thermometer inserted straight down into the center of the meat registers 145 degrees F for medium-rare, 65 to 75 minutes. Place the roast on a baking sheet and tent with foil. Allow to rest for 20 minutes.
For the sauce: In a saucepan add butter over medium heat and sauté mushrooms for about 7 minutes until soft. From the roasting pan pour juices from the rested meat, beef broth, marsala, arrowroot and rosemary. Bring to a boil, stirring constantly. Reduce the heat and simmer until thick, 15-17 minutes. Whisk in the butter until smooth and season with salt and pepper. Pour the sauce into a serving gravy boat.
Slice the roast into 1/2-inch-thick slices and arrange on a platter garnishing with rosemary. Set gravy boat next to platter.