Running down the center of a parsnip is a tough woody core that should be removed before cooking. Here’s how:
After trimming the ends and peeling the parsnip, quarter it lengthwise. Hold a sharp paring knife parallel to the cutting board and slowly run the knife between the core and the tender outer part of the parsnip. The core curves with the shape of the parsnip, so you won’t be able to get it all, but that’s fine—just remove as much as you can without sacrificing too much of the tender part.