spice-perfumed shoulder of lamb

from Deborah Golden - gorgeous!

for 6

2.5kg shoulder of lamb
2 heaped tsp sumac
4tbsp edible rose petals (rosewater?)
1 tbsp cumin ground
1/2 tbspground cinnamon
1/2 tbsp dried lime powder (or more sumac)
vegetable oil
2 tsp crushed sea salt

Oven at 160/140 fan
Place the lamb in a roasting tin lined with nonstick baking paper
Grind all the spices inc rose petals together until the petals are ground as finely as possible.
Drizzle a little oil onto the lamb and rub it all over, then sprinkle the spices and salt onto the lamb, making sure they adhere
Roast for 4 hours, then remove, cover with foil for 10 minutes, leave to rest before serving.  Should literally come apart with a fork.

Serve with green salad (tabbouleh?), potatoes or rice.