In a heavy kettle heat the oil over moderately high heat until it is hot but not smoking and in it brown the lamb necks. Add the onion and the garlic and cook the mixture, stirring, for 10 minutes, or until the onion is golden. Add the water, the broth, the wine, the parsley, and the carrot, bring the liquid to a boil, skimming the froth, and simmer the mixture, uncovered, for 2 hours. Transfer the lamb necks with tongs to a cutting board, discard the fat and bones, and chop the meat coarse. Add the meat to the kettle with the mint, the rosemary, and the spinach, bring the liquid to a boil, and add the couscous. Boil the soup, stirring, for 5 minutes, or until the couscous is tender, and season it with salt and pepper.

Makes about 11 cups, serving 6 as a main course.