Combine first five ingredients in a large bowl and stir well.Add zucchini, bell peppers, onion, and mushrooms; toss well to coat.Arrange vegetables in a single layer on a shallow roasting pan.Bake for 25 to 30 minutes or until tender (stir every 10 minutes or so).
Spoon roasted vegetables over couscous. Garnish with fresh basil sprigs if desired