Place the lamb into a large mixing bowl with the garlic, ras el hanout and the olive oil. Season with sea salt and toss to combine completely. Leave the lamb to sit covered in the fridge for at least one hour. Alternatively make this ahead of time and leave to marinate overnight.
While the lamb marinades, prepare the yoghurt sauce by infusing the saffron strands in hot water in a small mixing bowl and leaving to stand for 5 minutes. Add the remaining ingredients and mix well to combine. Season to taste and set aside.
Once the spices have permeated the meat, thread the lamb pieces onto 8 metal skewers and arrange on a large baking sheet. Place the lamb skewers to cook over a hot BBQ or a scorching hot griddle pan for 3 minutes either side or until medium rare. Turn as needed until you have a lightly charred exterior and a blushing interior. While the lamb cooks, toast the pita breads on the BBQ or just in a toaster.