- Mix the butter together with the garlic, thyme, cumin, ground ginger, turmeric and a really good pinch of salt and pepper. Score the lamb and pat the meat dry. Rub the butter all over the lamb. Cover and leave to marinade for as long as you can. Overnight in the fridge is best.
- Preheat the oven to 160 fan and get the lamb to room temperature. Chuck the onions into a roasting tray – use a snug tin so everything stays juicy. Mine is 25cm x 35 cm – and top with the lamb. Poke the preserved lemons into the cavities and pour in the stock around.
- Crumple some baking paper, large enough to cover the meat and wet it under the cold tap. Cover the lamb with the baking paper and then foil. Bake for 3 ½ – 4 hours or until the meat fall apart when you pull it with two forks. Baste the meat with the juices. Cover and again and leave to rest for 20 minutes.
- Pour all the juices from the roasting tray into a pan and skim off the fat. Bring to the boil over a low heat.
- To serve, place the onions onto a serving platter and discard the preserve lemons. Shred the meat, removing any fat and bone. Place onto the platter. Drizzle over a little gravy and serve immediately with mash and remaining gravy in a jug.
100g butter at room temperature
8 cloves garlic, crushed
3 tsp dry thyme
3 tsp ground cumin
2 tsp ground ginger
1 tsp turmeric
2.3 kg Waitrose British Whole Leg of Lamb
3 onions, roughly sliced
4 preserved lemons, halved
400ml lamb stock
A small handful of finely chopped parsley leaves
Mash potatoes to serve
Salt and pepper