In a heavy medium saucepan, whisk together the stock, cinnamon, ginger, cumin, and turmeric. Add the couscous in a slow steady stream, stirring constantly, and continue to boil, stirring, for 1 minute. Cover the pot tightly, remove from the heat and let stand for 15 minutes. Fluff the couscous grains with a fork, transfer to a large mixing bowl and let cool. Then fluff again, rubbing with your fingers to break up any lumps. Add the carrot, bell pepper, cucumber, onion, apple, currants and chick peas and toss. In a small jar with a lid, shake the remaining half tablespoon olive oil with the lemon juice, salt and pepper until well mixed. Pour over the salad and toss well. Cover and refrigerate for several hours or up to 3 days. Season with additional salt, pepper and lemon juice to taste before serving