1. Start by preparing the cheese spread. Place all of the ingredients in a food processor, pulsing well until mixture is homogeneous and fairly smooth.
2. Transfer to a small bowl, cover and refrigerate. Bring it to room temperature 5 to 10 minutes prior to spreading on pizza.
3. Then, grill the vegetables. Brush all vegetables with oil. If using a gas or charcoal grill, place brushed vegetables on a grill rack over medium-low heat.
4. If using a griddle, heat it over large burner on medium to medium-low heat, brush its surface with oil as well, and then grill vegetables.
5. Times vary from one vegetable to the other. For corn, grill for about 15 to 20 minutes (grill) or 8 to 10 minutes (griddle), or until cooked and grill marks appear; cut corn kernels off the cob. For red onions, about 3 minutes per side. For carrots, about 2 to 3 minutes per side. For zucchini, about 2 minutes per side or until grill marks appear. For grape tomatoes, which can be skewered or not, approximately 1-1/2 to 2 minutes per side, or just until grilled marks appear. Of course, you can replace any of these vegetables, customizing according to your preference.
6. Place all grilled vegetables in a platter and cover.
7. Finally, brush pitas with oil on both sides and grill for about 1 to 2 minutes per side or just until warm and grill marks appear.