Wipe the meat with damp kitchen paper and drizzle with 1 tablespoon of the olive oil. Season well with salt and pepper, rubbing it all over the meat. Pour the remaining tablespoon of olive oil into a roasting tin and heat in the over for 5 minutes. Add the onions, carrots and celery, tossing to coat. Season to taste and roast for 15 minutes.
Reduce the oven temperature to 190⁰ C. Remove the roasting tin from the oven and sit the beef on the bed of vegetables. Roast the beef for 1 hour for medium. If you prefer it medium rare, take it out 5-10 minutes earlier. For well done, leave in for another 10-15 minutes.
Remove the beef from the tin and place on a large dish. Rest in a warm place for at least 20 minutes before carving. To make the gravy, stir the potato flour into the juices in the roasting tin and then gradually stir in the stock. Place directly on the hob to simmer for 5 minutes, stirring and scrapping the bottom with a wooden spoon to release any sediment. Season and pour through a sieve into a gravy boat, discarding the vegetables that the beef has been roasted on.
Carve the beef into slices and arrange on warmed plates. Serve with roasted root vegetables and hand round the gravy and horseradish creme fraiche separately.
You can ask your butcher for a cube roll of beef, which is an excellent cut for roasting and perfect when you`ve got to feed a crowd. Always allow a joint to come back up to room temperature before roasting to achieve the best flavour.