Your choice of:
1 Spanish or other large onion, ends trimmed, halved through its equator
2 red or yellow bell peppers, stemmed, halved, and seeded
1 eggplant, cut into 1/2-inch-thick slices
1 zucchini, cut lengthwise into 1/2-inch-thick slices
1 bunch scallions, bottoms trimmed
3 endives, halved lengthwise
2 heads radicchio, halved lengthwise
4 portobello mushroom caps
Extra-virgin olive oil for brushing
Salt and freshly ground black pepper, to taste
Garnish: minced parsley leaves
Special equipment: bamboo skewers, soaked in water 1 hour before using
Start a multilevel charcoal fire or preheat your gas grill to medium high. Brush all the vegetables with olive oil and sprinkle with salt and pepper. Thread vegetables, except scallions, on two parallel skewers. Place scallions directly on grate.
Grill, turning once or twice, until nicely browned on both sides and tender throughout, about 15 minutes (delicate vegetables, such as the scallions, will finish sooner; set aside). Drizzle with a little more olive oil, garnish, and serve hot or at room temperature.