Foodies love to say that you’ve never had wasabi until you’ve had the fresh root itself, grated directly on your sashimi. This is true. But we fine Americans have our own Wonderroot, a root that shows up on sandwiches and accompanying steaks, but usually after being held prisoner in a jar or tub.I’m talking about horseradish. From the garden, it looks like a giant carrot, as big as and as colorful as a jaundiced, leathery arm. Inside, the white flesh is , more pungent than anything you get in a jar.