Whether served as a side vegetable or as the main entree, grilled vegetable kababs are an easy, colorful, and tasty dish to include at your summertime cookout. In this recipe, the vegetables are first marinated in a dijon-herb mixture and then grilled, resulting in vegetable kebabs that are bursting with flavor. Use as a side dish to grilled meats or simply serve by themselves over a bed of couscous.