Step 1

Place turnips in a large skillet; add water to cover turnips halfway. Add butter, sugar, and a large pinch of salt; bring to a boil. Cook, stirring occasionally, until liquid is syrupy and turnips are tender, about 15 minutes. (If turnips are tender before liquid has reduced, use a slotted spoon to transfer turnips to a plate and reduce liquid until syrupy. Return turnips to pan and stir to coat well.) DO AHEAD: Can be made 4 hours ahead. Let stand at room temperature. Rewarm before continuing.

Step 2

Add turnip greens to skillet and cook over medium heat, stirring occasionally, until just wilted, 2–3 minutes. Season with salt.