• 1/2 cup chopped onions (about 1 medium onion)
• 8 cloves garlic , peeled
• 3 Tbsp. olive oil
• 2 Tbsp. chopped fresh rosemary
• 2 Tbsp. chopped fresh thyme
• 1 Tbsp. dried sage
• 3 Tbsp. freshly ground black pepper

• 1 (10-pound) bone-in prime rib of beef , fat trimmed to 1/4-inch thick
• 1/4 cup plus 1 1/2 tsp. coarse salt
• Herb rub (recipe above)
• 3 pounds fingerling potatoes , unpeeled
• 10 small red onions (about 3 pounds), peeled and quartered
• 1/4 cup olive oil
• 3/4 tsp. freshly ground black pepper

To make rub: In a food processor fitted with knife blade, process onion, garlic, and olive oil 1 minute, or until blended. Add rosemary, thyme, sage, and pepper. Process until combined.

Using a sharp knife, score the fat on roast in crosshatch pattern, cutting about 1/4 inch deep. Rub roast all over with 1/4 cup salt; follow with herb rub. In a 17" x 12" roasting pan, place roast fat side up; cover and refrigerate 4 to 6 hours. Remove from refrigerator and let stand at room temperature 1 hour before cooking.

Preheat oven to 450°, placing racks in center and lower third of oven. Place roast on center rack; cook 20 minutes. Reduce temperature to 325° and continue to cook about 40 minutes.

Meanwhile, place potatoes and onions in a large bowl. Toss with olive oil, pepper, and remaining 1 1/2 teaspoons salt. After roast has been in the oven 1 hour total, place about 1/4 of the vegetables around the roast; scatter remaining vegetables in another 17" x 12" roasting pan. Place in oven and cook until a meat thermometer inserted into thickest part of the roast reads 130° and vegetables are tender, about 2 hours 15 minutes. Remove from oven. Place roast on carving board and tent with foil; let stand 20 minutes before carving.

Meanwhile, pour pan drippings into a bowl; skim fat off top. Using a slotted spoon, transfer vegetables to serving bowls. Slice roast and serve with pan juices, vegetables, and Apple-Quince Compote.