Saute the leek in the butter until it is soft. Add the chicken stock, salt, and pepper and bring the stock to a boil. Add the carrot and turnip and cook for 8 minutes. Add the red pepper, chickpeas, and zucchini and cook for 2 minutes longer. Add the couscous, stir, cover, and steam for 5 minutes. If the mixture seems dry, add more hot chicken stock. Serve hot.
Serves 6 to 8