Pre-heat oven to 150◦C-160◦C. Take the lamb out of the fridge at least 30 minutes before starting this recipe.Rub half the olive oil, sumac, half the Baharat, sea salt and pepper into the lamb.
Heat remaining oil in frying pan, add garlic, carrot, celery, and onion and cook for 3-5 minutes or until soft and translucent.Remove to a gastronome.Add lamb, cook for 3-5 minutes each side to caramelise.Place on top of mirepoix.Pour in stock.Cover tightly with a layer of baking paper, followed by a layer of foil.Cook, covered, for 4 hours.Remove lamb.
Place lamb in a clean gastronome, squeeze over lemon juice, sprinkle with remaining Baharat, season with extra salt and pepper.Increase oven to high heat.Place back in oven and cook for a further 20 minutes to caramelize.
Remove the lamb from the oven to rest. Serve with accompaniments.