Roasted Root Vegetable Medley

Name: Roasted Root Vegetable Medley
Ingredients: 8 to 12 slender carrots, peeled and trimmed; 8 to 12 baby turnips, peeled; 6 to 8 fingerling potatoes, scrubbed and cut lengthwise in halves; 1 or 2 large parsnips, peeled, trimmed, and cut diagonally into 1-inch-thick slices; 1 or 2 medium onions, trimmed, peeled and halved, each 1/2 cut into quarters; 1 or 2 large beets, peeled and cut into thick wedges; 1 or 2 kohlrabi bulbs, peeled and cut into thick wedges; 1 celery root, trimmed and halved, halves cut crosswise into 1-inch-thick slices; 1 whole head garlic, separated into cloves, unpeeled; 2 or 3 sprigs fresh rosemary, sage, or thyme; Salt; Freshly ground black pepper; Extra-virgin olive oil