Heat your oven to 220°C/Fan 200°C/Gas 7. Unwrap your meat. Pat it dry and put it in a roasting tin. Let it get up to room temperature.
Finely grind your star anise using a spice or coffee grinder or a pestle and mortar. Alternatively, pound it in a metal bowl with the bottom of a jam jar.
Mix the star anise with the chilli flakes. Use a pinch for milder heat or more than 1 tsp for a good kick.
Massage the spices all over the lamb. Tuck some into the little grooves where the meat has been rolled, too, if you can. Dust a little sea salt and pepper over the top, then drizzle with the olive oil.
Once the meat is at room temperature, slide into the centre of the oven. Roast for 20 mins.
Lower the heat to 180°C/Fan 160°C/Gas 4. Roast for a further 45 mins. Set the lamb aside to rest for at least 30 mins before carving.
The meat will be a little pink in the centre. If you like well-done lamb, arrange carved slices in a baking dish, slightly overlapping. Pour some of the pan juices over. Cover with foil. Cook in the oven for 10-15 mins or till the meat is done to your liking.
The pan juices are stunning on their own – simply drizzle over the carved meat. If you want a proper gravy, sizzle 4 tbsp of the pan juices with 250 ml red wine and 1 tsp honey till rich and flavourful, adding more wine, honey or pan juices as you fancy.