Oxtail Consommé with Sherry

Description
This rich beefy oxtail consommé takes two days to prepare, as the oxtail stock must be refrigerated overnight. If you choose to skip the clarification, you will end up with a fine oxtail soup. If you do clarify the stock, your perseverance will be rewarded with a stunning golden broth with an intense beef flavor. You can use large oxtail pieces, or use up all those small pieces from the ends of oxtails that you have stored in the freezer. Dry sherry is the classic drink pairing for consommé.
 * Serves 12

Ingredients

 * 4 carrots, sliced
 * 4 celery stalks, sliced
 * 2 onion, unpeeled, cut into wedges
 * 9 pounds (4 kg) oxtail pieces
 * 1 cup (250 ml) dry sherry
 * 4 thyme sprigs
 * 2 bay leaf
 * 1/2 teaspoon black peppercorns

For clarifying

 * 1 small carrot, diced
 * 1 celery stalk, diced
 * 1 small leek, diced
 * 6 ounces (175 g) lean ground beef
 * 2 egg whites
 * kosher salt
 * extra dry sherry, if serving the consommé hot

Directions

 * 1) Preheat the oven to 425°F (220°C). Scatter the carrots, celery, and onion over the bottom of a large roasting pan. Rinse the oxtail pieces well under cold running water and pat dry, then place them on top of the vegetables. Roast for 1 hour, turning the oxtail pieces after 30 minutes.
 * 2) Using tongs, transfer the oxtail and vegetables to a large stockpot. Discard any fat from the roasting pan. Add the sherry with 4 cups (1 l) water, place over medium-low heat, and bring to a boil, deglazing the pan by scraping up the browned bits from the bottom. Pour this liquid into the stockpot and add 20 cups (5 l) cold water. Bring just to a boil, then reduce the heat so that the liquid simmers, and skim off the foam. Add the thyme sprigs, bay leaf, and peppercorns and simmer gently for 5 hours, skimming from time to time.
 * 3) Strain the stock through a sieve into a large bowl. Discard the debris left in the sieve and cool the stock quickly by placing the bowl in a larger bowl or sink filled with ice water; stir occasionally as it cools, then refrigerate overnight.
 * 4) The next morning, you will have a jellied liquid topped with fat. Remove the fat and discard the debris at the bottom of the bowl. You should have about 12 cups (3 l) stock; if you have more, reduce it by boiling, then allow to cool. To clarify it, the stock must be cold but not jelled. Reheat gently to liquefy if necessary.
 * 5) Place the diced carrot, celery, and leek in a food processor and process until finely chopped. Add the meat, egg whites, and 2 tablespoons of water and blend until well mixed. Stir this mixture into the stock and bring to a boil over medium-high heat, stirring constantly with a spatula or wooden spoon and scraping the bottom of the saucepan to prevent the egg white from sticking. As the liquid approaches the boil, it will appear to curdle; don't panic, that is what you want. As soon as the stock begins to boil, stop stirring, and remove the saucepan from the heat. The whites will form a congealed mass on the surface, which will puff up and then crack as the steam escapes.
 * 6) Reduce the heat to very low and return the saucepan to the heat, making a larger hole in the egg white mass with a spoon to allow the steam to escape. Simmer very gently — you want to see the small bubbles of steam break through the hole in the egg white mass — for 45 minutes. Remove the saucepan from the heat and let stand for 5 minutes.
 * 7) Line a sieve with a double thickness of damp cheesecloth or a dampened thin cotton tea towel, and place over a bowl. Using a skimmer or large slotted spoon, carefully lift off as much of the egg white mass as you can and set aside in another bowl. Ladle the consommé into the sieve and allow it to drip slowly through the cloth. As you get closer to the bottom of the saucepan, you might notice that the clear consommé is being muddied by bits of egg white. Don't worry, just add it to the sieve. Check the bowl with the egg white debris and pour any liquid that has escaped from it into the sieve. Allow all the liquid to drip slowly through the sieve; don't be tempted to press on the egg whites, as that would cloud the consommé.
 * 8) You will have about 10 cups (2.5 l) clear consommé in the bowl and a mess of congealed egg white to discard. Season the consommé with about 1/2 teaspoon salt. Serve hot, or allow to cool, then chill and serve it cold. If serving hot, pour 1 tablespoon dry sherry into each bowl before ladling in the consommé. If you serve it cold, you will probably need to boost the seasoning, as cold dulls the flavor. Garnishes for beef (and oxtail) consommé: consommé speaks for itself, but if you wish to add something, keep it simple so that the consommé isn't overpowered by the garnish.