Rinse the zucchini and cut lengthwise into slices. Rinse the eggplants, cut lengthwise into slices and place in cold salted water. Peel the carrots and cut lengthwise into strips.
Rinse the bell peppers and roast under the broiler until the skin blisters. Halve the peppers, remove the skin and remove the seeds.
Remove the eggplant from the brine and pat dry with kitchen paper.
Mix 200 ml of olive oil (approximately 3/4 cup) with the garlic and brush all vegetables with it. Season them with salt and pepper.
Place the vegetables on a charcoal barbecue and grill on all sides.
Arrange on a plate and place thyme sprigs between them. Leave to infuse briefly and serve with crusty white bread if desired.