Place the lamb in a non aluminium container. Combine all the marinade ingredients and rub over the lamb. Cover and refrigerate overnight or for 2-3 hours at room temperature.
Remove the lamb from the marinade, reserving the marinade, and sprinkle with salt.
Heat a griddle until very hot and cook the lamb for 12-15 minutes each side, basting every so often with the reserved marinade.
To make the couscous, heat the stock in a pan until boiling, then remove from the heat. Pour in the couscous, and then stir in the lemon zest. Cover with clingfilm and set aside for 5
minutes to allow the grains to swell. Remove the clingfilm and fluff up the grains with a fork so that they separate.
Return the couscous to the heat and drizzle over the olive oil. Cook gently for a few minutes, stirring with the fork to fluff up the grains, then remove from the heat. Fold in the almonds, apricots, sultanas, parsley and coriander and season to taste. Tip into a dish and serve.