Ingredients

Step by step

1. Remove the beef from the fridge 30 minutes before you begin. Preheat the oven to 190°C, fan 170°C, gas 5. Remove the packaging and string from the beef and pat it dry with kitchen paper. Heat a dry frying pan until hot. Rub the beef all over with 1 teaspoon oil, then sear in a hot pan, turning until browned all over – this should take about 5 minutes. Remove to a board, cool for 5 minutes, then season all over with black pepper and the mustard powder. Wrap the pancetta slices around the beef, overlapping until completely covered. Tie with 2 or 3 pieces of string to hold in place. Tuck half of the sprigs of thyme under the string.
2. Cut the unpeeled beetroot into even-sized wedges and spread out in a medium roasting tin (just big enough for the beetroot to be in a single layer). Remove the leaves from the remaining sprigs of thyme and add these to the tin with 1 tablespoon of olive oil. Season and toss together. Put the beef on top of the beetroot.
3. Roast in the oven for 35 minutes (for medium), or 40-45 minutes for more well done. Remove from the oven and lift the beef onto a board, then loosely cover with foil and rest for 15 minutes. Increase the oven temperature to 220°C, fan 200°C, gas 6. Cover the tin with the beetroot with foil and return to the oven for 15 minutes while the beef rests.
   Tip

   With a small joint of beef, it's best to sear it first in a pan – rather than starting the joint off at a higher oven temperature – to prevent overcooking.
4. In a bowl, stir the horseradish into the crème fraîche and season.
5. Toss the beetroot with a large handful of rocket and transfer to a serving dish. Carve the rested beef and serve with the rocket, beets and horseradish crème fraîche.