Preheat your oven to 200ºC/400ºF/gas 6. Wash and scrub the beetroots thoroughly to remove any dirt or grit, place in a pan of cold salted water and bring to the boil, then simmer for about 50 minutes. Meanwhile, put all the marinade ingredients and a few generous pinches of salt in a pestle and mortar or Flavour Shaker, bash them up, add a couple of lugs of olive oil and rub all over your beef joint. Put the joint on a large roasting tray and into the preheated oven for an hour.
When your beetroot is almost cooked, drain and peel while still warm, then cut each one in half and toss all the pieces in a bowl with the garlic, thyme sprigs, balsamic vinegar and a few lugs of olive oil. After its hour is up, remove the beef from the oven and scatter the beetroot halves all around the meat in the tray. Place the tray back in the oven and cook for a further 30 minutes, by which time the beef should be medium and the beetroot perfectly roasted (feel free to cook the meat to your liking, though). Allow the meat to rest for up to 20 minutes – you may need to keep the beetroot warm in a low oven.
Chop the marjoram or parsley leaves and mix with the crème fraîche and lemon juice. Spike well with the horseradish and season to taste. Carve the beef on to a large platter with the resting juices. Serve with the roast beetroots, flavoured crème fraîche and some lovely roast potatoes.
Matt’s wine suggestion: Australian red – Shiraz