Lightly coat sweet pepper, eggplant, zucchini, and mushroom with cooking spray. For a charcoal grill, place vegetables on the rack of an uncovered grill directly over medium-hot coals. Grill for 3 minutes; turn vegetables. Grill 3 to 5 minutes more or until vegetables are crisp- tender. (For a gas grill, preheat grill. Reduce heat to medium. Place vegetables on grill rack over heat; cover and grill as above.) Remove vegetables from grill; cool slightly.

Coarsely chop vegetables. In a medium bowl toss together chopped vegetables, garlic, and pepper. Divide vegetables among tortillas, placing vegetables just below center and to within 1 inch of the edge. Sprinkle vegetables with cheese. Fold bottom edge of each tortilla up and over filling. Fold opposite sides in over filling. Roll up from the bottom.

Return filled tortillas to grill rack. Grill for 1 minute; turn and grill 1 to 2 minutes more or until tortillas are lightly browned. Serve with tomato (if using), Cilantro Pesto and if desired, avocado and sour cream.

In a blender or food processor, combine 1-1/2 cups firmly packed cilantro leaves, 2 tablespoons toasted pine nuts, 1 tablespoon grated Parmesan cheese, and 1 clove minced garlic. Cover and blend or process with several on-off turns until a paste forms, stopping the machine several times and scraping down the sides. With the machine running, gradually add 3 tablespoons olive oil and 1 tablespoon water; blend or process until smooth. Cover the surface with plastic wrap and store in a tightly covered container in the refrigerator for up to 2 days.