Prep 25 mins
Cook 3 hrs
- 8 lbs boneless beef rib roast, about, tied with kitchen string
- 3⁄4 cup heavy cream
- 1 cup sour cream
- 1 lemon, juice of
- salt & freshly ground black pepper, to taste
- 1⁄2 cup freshly grated horseradish or 1⁄2 cup prepared horseradish
- 4 tablespoons olive oil
- 1 tablespoon finely minced garlic
- 2 large carrots, chopped
- 3 stalks celery, chopped
- 1 leek, white and light green portions, chopped and rinsed well
- 5 cups unsalted beef stock
- 4 sprigs fresh thyme, plus
- 1 teaspoon chopped fresh thyme
- Let the beef roast stand at room temperature for about 1 hour.
- In a nonreactive bowl, combine the heavy cream and sour cream and whisk until smooth.
- Add the lemon juice, salt, pepper and horseradish and whisk until blended.
- Cover and refrigerate until ready to serve.
- Position a rack in the bottom of an oven and preheat to 350°F.
- In a small sauté pan over medium heat, warm 2 Tbs of the olive oil.
- Add the garlic and fry, stirring constantly, until golden, 1 to 2 minutes.
- Remove the pan from the heat and immediately skim the garlic from the oil, reserving the garlic.
- Season the beef generously with salt and pepper and rub the fried garlic over the roast.
- Set the beef on a rack in a roasting pan and roast until an instant-read thermometer inserted into the center of the meat registers 125°F for very rare to rare, 1 3/4 to 2 hours; or 130°F to 135°F for medium-rare to medium, 2 1/4 to 2 3/4 hours.
- Transfer the roast to a carving board, tent loosely with aluminum foil and let rest for 20 minutes before carving.
- (The roast will continue to cook as it rests, so you can remove it from the oven 3 to 4 degrees below the desired temperature). Meanwhile, in a medium saucepan over medium-high heat, warm the remaining 2 Tbs oil.
- Add the carrots, celery and leek, and sauté until tender and golden, 6 to 8 minutes.
- Add 4 cups of the stock and the thyme sprigs, bring to a simmer and reduce the heat to low.
- Simmer until the liquid is reduced by half, about 1 hour.
- After removing the roast from the pan, set the pan over medium heat, pour in the remaining 1 cup stock and whisk to scrape up any browned bits.
- Pour the pan juices into the simmering broth, add the chopped thyme and simmer for 10 minutes.
- Strain the sauce through a fine-mesh sieve set over a bowl.
- Skim the fat, adjust the seasonings with salt and pepper, and transfer to a sauceboat or pitcher.
- Carve the beef into 1/2-inch-thick slices and pass the sauce and the horseradish cream alongside.