Mechoui lamb with carrot & orange salad

INGREDIENTS

• 1 quality shoulder of lamb, approximately 2.5kg
• 50 g smen or butter, at room temperature
• 1 heaped teaspoon ground cumin, plus extra to serve
• 1 heaped teaspoon ground coriander, plus extra to serve
• 1 teaspoon sea salt
• 1 small handful fresh thyme sprigs, leaves picked
• a few sprigs fresh rosemary, leaves picked
• freshly ground black pepper
• 1 bulb garlic
• 4 flatbreads
• ½ pomegranate, seeds of
• 250 g Greek yoghurt
• 4 tablespoons harissa