Step 1

For the chermoula spice, place all the spices and 1 tbs sea salt flakes in a medium frypan over medium heat. Toast the spices, shaking pan and tossing spices for 1-2 minutes until toasted and fragrant. Transfer to a bowl and cool completely. Once cooled, transfer to an airtight container.

Step 2

To marinate the lamb, place half of the onion, coriander, garlic, ginger, yoghurt and 3 tbs chermoula spice in a food processor and pulse until finely chopped and combined. Season to taste. Place lamb in a large non-reactive bowl or container and rub the chermoula yoghurt all over. Season and cover with plastic wrap. Chill overnight to marinate.

Step 3

Remove lamb from fridge and stand until lamb returns to room temperature.

Step 4

Meanwhile, preheat oven to 160°C. When lamb is at room temperature, place on a wire rack over a roasting pan and spoon over any extra marinade left in the bowl. Place a sheet of baking paper over lamb and seal roasting pan with foil. Slow roast for 4-5 hours until lamb is tender and falls off the bone. Remove foil, increase oven temperature to 240°C. Continue to roast, uncovered, for 30 minutes until lamb has browned on top. Remove from oven and rest for 15 minutes before serving.

Step 5

Serve lamb on a large platter with remaining onion, cucumber, tomato, extra yoghurt, lime wedges and charred flatbread. Scatter with more chermoula spice to serve.