Place vegetables, garlic cloves, and thyme leaves in a roasting pan. Drizzle with olive oil, add salt and pepper, and toss to coat.
Roast for 45 minutes, turning every 15 minutes. Add the vinegar over the top and continue to roast for another 10 minutes or until the vegetables are fork-tender. Remove the thyme sprigs.
Serve on a serving dish garnished with fresh thyme leaves.