Preheat grill to medium-high. Place vegetables on a tray and drizzle with 1 tbsp (15 mL) of the olive oil; season with salt and pepper. Set aside.
Whisk together pesto and vinegar in a small bowl. Slowly whisk in olive oil and set aside.
Place onion on hot grill; after 3 min., add peppers and asparagus, then zucchini. Turn vegetables as needed, grilling for 8 to 10 min. in total. Just before other vegetables are done, place tomato quarters on grill for 30 seconds. Transfer grilled vegetables to a platter, drizzle with the pesto dressing and sprinkle with goat cheese.