For this dish, you’ll need enough lit charcoal to keep burning steadily for at least 2 hours!
- Toast the seeds in a small, dry frying pan, swirling them often over a medium heat (on the barbecue grill or the hob), until fragrant. Tip into a pestle and mortar or spice grinder and work to a medium-fine powder. Add the garlic, grated ginger and any ginger juice, the orange zest, thyme and seasoning, then work to a paste.
- Smear the paste generously over the lamb, making sure any of the rub that falls on the work surface makes its way back onto the lamb.
- Grill the lamb on the hot barbecue or Big Green Egg for 3 minutes on each side until well coloured but not burnt. If flames flare up from the dripping fat, gently move the lamb away from them. Transfer the lamb to a baking tray lined with a double layer of foil. Pour in a glass of water and loosely scrunch another double layer of foil over the top of the lamb. Put the tray on the barbecue grill, then shut the lid, making sure the air vents are two-thirds closed on the top and bottom (to keep the temperature between 180-200°C).
- Cook the lamb for 2 hours. Check it every half hour – if it appears to be burning or the juices in the tray seem to be boiling away, add more water.
- About 15 minutes before the lamb is ready, remove the covering foil and shut the lid again. When cooked, rest the lamb on a platter, covered with foil, for 15 minutes or so. Serve the lamb with the juices poured over.