Preheat the oven at 425ºF/ 218°C. Remove the greens from the carrots. (For a prettier presentation, keep 1 inch of the carrot tops.) Wash carrots in plenty of water, peel and cut in halves lenghtwise.
Place salt, pepper, olive oil, additional seasonings if using, and carrots in a large bowl. Toss well to coat.
Line a large baking sheet with foil. Transfer the seasoned carrots to the baking sheet, spread evenly, and arrange in a single layer.
Place tray in the oven, cover with foil and roast for 15 minutes. Remove foil, bake another 15 to 30 minutes, until tender and slightly caramelized.
Remove carrots from the oven, place on a serving platter. Add the parsely or other garnishes. Taste, if needed, add salt and pepper.