Preheat the oven to 400°F and adjust the oven rack to the center position for even roasting. For easier cleanup, line a baking sheet with parchment paper.

Remove the green tops from the baby carrots. Peeling is optional, especially if the skins are tender and clean. Arrange the carrots in a single layer on the prepared baking sheet. Using a pastry brush or spoon, coat the carrots generously with olive oil, ensuring each piece is well covered. Season with sea salt and a few grinds of black pepper to taste.

Place the baking sheet in the oven and roast the carrots for 40 to 45 minutes, or until they are fork-tender and the edges are beginning to caramelize and turn golden brown. If you're including shallots or red onion, scatter the slices over the carrots halfway through the roasting time to allow them to soften and develop a touch of sweetness without burning.

Keep an eye on doneness, as oven temperatures may vary. Serve warm as a simple yet flavorful side dish that highlights the natural sweetness of the carrots.