Prime Rib Roast and Roasted Onion Medley
1 3-rib prime rib roast 7 pounds
1 tablespoon olive oil
1 packet peppercorn and garlic dry marinade mix 1.13 ounces
2 teaspoons coarse kosher salt
Roasted Onion Medley
1/2 cup balsamic vinaigrette
1 teaspoon dried thyme
1/2 teaspoon salt
1/2 teaspoon pepper
3 red onions peeled and cut into eighths
4 shallots peeled and quartered
1 bag frozen pearl onions 1 pound, thawed
For prime rib: Line a large roasting pan with foil. Rub roast evenly with olive oil. In a small bowl, combine marinade mix and salt. Rub on all sides of roast. Place, fat side up, rib side down, in roasting pan. Cover and refrigerate at least 4 hours, or overnight. Remove from refrigerator and let stand about 3 hours, or to room temperature.
For roasted onions: In a medium bowl, combine vinaigrette, thyme, salt, and pepper. Add red onions, shallots, and pearl onions, tossing gently to coat. Line a rimmed baking sheet with foil and spread onion mixture in a s ingle layer.
Preheat oven to 450°F. Roast medley until tender, about 45 minutes, stirring halfway through time. Remove from oven.
Lower oven temperature to 325°F. Bake roast until internal temperature of thickest portion reaches 145°F for medium (about 2 hours) or to desired degree of doneness. Let stand for 10 minutes before carving. Garnish with roasted onions.