2 750-ml bottles Cabernet Sauvignon
4 cups beef stock or canned broth
2 cups ruby Port
3 large garlic cloves, peeled
1 large shallot, peeled, halved
2 bay leaves
3 teaspoons dried thyme
1 6-pound boneless prime rib beef roast
4 large garlic cloves, pressed
Fresh parsley sprigs
Combine first 6 ingredients and 1 teaspoon thyme in large non-aluminum saucepan. Boil until reduced to 2 cups, about 1 hour. (Cabernet mixture can be prepared 2 days ahead. Cool, cover and refrigerate.)
Preheat oven to 450°F. Place beef, fat side up, in heavy 13x9x2-inch baking pan. Rub beef all over with pressed garlic and remaining 2 teaspoons thyme. Season beef generously with salt and pepper. Roast 1 hour. Tent beef with foil. Continue roasting until meat thermometer inserted into center registers 118°F for rare, about 35 minutes. Transfer to platter and let stand 20 minutes.
Pour off all fat from roasting pan. Place pan over medium-high heat. Add Cabernet mixture to pan and bring to boil, scraping up any browned bits. Season to taste with salt and pepper. Pour jus into sauce boat. Garnish platter with parsley, if desired. Carve beef and serve, passing jus separately.