Step 1Remove beef from fridge at least 30min before cooking (up to 1hr) to allow it to come up to room temperature and take note of its weight.
Step 2Preheat oven to 220° (200°C fan) mark 7. Mix the mustard powder, 1tsp salt and plenty of ground black pepper and rub all over the beef. Put onions and thyme in the base of a sturdy roasting tin that will just fit the beef. Sit beef on top and roast for 20min.
Step 3Lower oven temperature to 160°C (140°C fan) mark 3 and continue cooking for 11/4hr (or 15min per 500g) for medium-rare meat (cook for longer or shorter as desired). Meanwhile, for the roasted garlic cream, cut the top off each garlic bulb and drizzle over the oil. Season and wrap each bulb loosely in foil. Cook alongside the beef for 1hr, then set aside to cool slightly.
Step 4Once cooked, transfer beef to a carving board and loosely cover with foil. Leave to rest in a warm place for at least 20min (up to 1hr).
Step 5Pour or spoon of excess fat from the roasting tin. Add port and bubble for a few min over medium hob heat, scraping the base of the tin with a wooden spoon to lift up any sticky bits. Strain into a pan (press the onions to extract any juices, then discard along with the thyme). Add the star anise and stock to the pan. Mix cornflour in a small bowl with a little of the gravy until smooth, then whisk into the pan and bubble for 10-15min, or until thickened to a good gravy consistency.
Step 6For the garlic cream, squeeze the garlic cloves out of their skins and mash into the crème fraîche with some seasoning.
Step 7Add any resting and carving juices to the pan of gravy. Simmer the gravy briefly again, then pour into a jug. Serve the beef, gravy and garlic cream with your chosen sides. To carve the beef, it’s easiest to first remove the joint from the bone and then slice the meat.
Get ahead
Make the garlic cream up to a day ahead. Cover and chill. Complete recipe to serve.
GH Tip
Forerib of beef is the rib-eye on the bone, while wing rib is the sirloin. Both make a fine joint for roasting and can be cooked in the same way and to the same timings.