This is a variation of the classic French Vichy carrots, which are cooked in Vichy mineral water. The Madeira gives them a delicious syrupy glaze.
Place the carrots in a shallow saucepan, top with the butter and sprinkle over the sugar. Season lightly with salt and pepper. Pour over the Madeira and enough Vichy water just to cover the carrots. Cover the surface with a piece of buttered greaseproof paper and then cover the pan with a lid.
Cook over a fairly high heat, shaking the carrots occasionally (do not stir them), for 10-15 minutes or until they are tender and coated in the glossy Madeira glaze.