Trim the ends and cut the rhubarb into little finger-size pieces.
Place the rhubarb in a shallow baking dish.
Add the sugar and toss together, shake the baking dish so rhubarb is in a single layer.
Cover with foil and roast for 15 minutes.
Remove the foil, the sugar should have dissolved.
Give the dish another shake, roast for another 5 minutes or until tender and the juices are syrupy. Test with a sharp knife, the rhubarb should be tender, not mushy and still have kept its shape. Serve warm over vanilla bean ice cream