Start with this mix of vegetables, or simply use what you have on hand.
Soak wooden skewers in water 30 minutes. (Omit if using metal skewers.)
Preheat grill to 350° to 400° (medium-high) heat. Thread tomatoes 1 inch apart onto skewers. Snap off and discard tough ends of asparagus.
Brush zucchini, next 5 ingredients, tomatoes, and asparagus with olive oil; sprinkle with desired amount of salt and black pepper.
Grill sweet potatoes, covered with grill lid, 6 minutes on each side or until tender. At the same time, grill zucchini, peppers, mushrooms, and eggplant 4 to 6 minutes on each side or until crisp-tender. Grill green onions, asparagus, and tomatoes 2 to 3 minutes on each side or until tender and grill marks appear. Remove from grill, and brush with vinaigrette. Arrange on a serving platter. Serve with remaining vinaigrette.