In a medium saucepan heat olive oil. Cook onion, pepper, carrot, and zucchini in hot oil for 5 minutes. Stir in stock, cabbage, tomatoes, coriander or parsley, salt, cardamom, caraway, and turmeric. Bring to boiling; reduce heat. Cover and simmer for 10 minutes. Uncover; stir in couscous. Remove from heat; let stand, covered, for 5 minutes. Uncover and fluff with a fork.
Meanwhile, for sauce, stir together yogurt or sour cream, mayonnaise, milk, basil, thyme, salt, and pepper.