Soak 18 wood skewers in water. In a bowl, combine 1/2 cup olive oil, the lemon peel, lemon juice, garlic, salt, ginger, cumin, turmeric and cinnamon; add cayenne to taste. Add the lamb and marinate, refrigerated, for 1/2 hour or up to 4 hours.
Thread 2 lamb cubes and 1 date onto each skewer; reserve the marinade. In a lightly oiled grill pan over medium-high heat, grill the meat until slightly charred, 3 to 4 minutes on each side, brushing with the marinade.
In a saucepan, bring the chicken broth to a boil. Add the couscous, remove from the heat and cover for 5 minutes. Fluff with a fork, then stir in 1/4 cup olive oil, the pistachios, mint and parsley. Serve with the kebabs.